{"items":[{"id":"NVI-00004730","kind":"vulnerability","title":"PHPSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion","revision":4,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-xh5m-36r6-47m3","CVE-2026-59933"],"plain_summary":"GitHub lists this reviewed advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-02e4f91369d378b489183a2723c57421"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 5.8.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 3.10.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.4.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.1.18 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 1.30.6 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-23T15:01:52.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-03e66163027143f55cc054719fff5fd0"},{"kind":"CVSS","as_of":"2026-10-23T23:10:00.157Z","value":"7.5 HIGH (3.1)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-c03601d096be8edfca45a9b830413f2e"},{"kind":"EPSS","as_of":"2026-11-04T12:03:12.000Z","value":"0.461%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.40091. Missing scores are unknown.","source_id":"sr-02e4f91369d378b489183a2723c57421"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-03e66163027143f55cc054719fff5fd0","url":"https://github.com/advisories/GHSA-xh5m-36r6-47m3","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-xh5m-36r6-47m3","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T17:42:43.803Z"},{"id":"sr-70c7746745a03cfe10099faa8a013b95","url":"https://github.com/advisories/GHSA-xh5m-36r6-47m3","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-xh5m-36r6-47m3","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:51.445Z"},{"id":"sr-c03601d096be8edfca45a9b830413f2e","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59933","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-59933","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-01T07:24:39.943Z"},{"id":"sr-02e4f91369d378b489183a2723c57421","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-59933","publisher":"FIRST EPSS","observed_at":"2026-11-04T23:33:33.055Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 4.0.0, <= 5.8.0"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 3.3.0, <= 3.10.6"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 2.2.0, <= 2.4.6"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 2.0.0, <= 2.1.17"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["<= 1.30.5"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 4.0.0; fixed 5.8.1"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 3.3.0; fixed 3.10.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.2.0; fixed 2.4.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.1.18"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 1.30.6"]}],"null_published_at":"2026-11-07T22:29:23.381Z","source_updated_at":"2026-07-23T15:01:52.000Z","source_disclosed_at":"2026-07-23T15:01:50.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:42:51.445Z"},{"id":"NVI-00004730","kind":"vulnerability","title":"PHPSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-xh5m-36r6-47m3","CVE-2026-59933"],"plain_summary":"GitHub lists this reviewed advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-02e4f91369d378b489183a2723c57421"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 5.8.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 3.10.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.4.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.1.18 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 1.30.6 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-23T15:01:52.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-03e66163027143f55cc054719fff5fd0"},{"kind":"EPSS","as_of":"2026-11-04T12:03:12.000Z","value":"0.461%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.40091. Missing scores are unknown.","source_id":"sr-02e4f91369d378b489183a2723c57421"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-03e66163027143f55cc054719fff5fd0","url":"https://github.com/advisories/GHSA-xh5m-36r6-47m3","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-xh5m-36r6-47m3","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T17:42:43.803Z"},{"id":"sr-70c7746745a03cfe10099faa8a013b95","url":"https://github.com/advisories/GHSA-xh5m-36r6-47m3","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-xh5m-36r6-47m3","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:51.445Z"},{"id":"sr-02e4f91369d378b489183a2723c57421","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-59933","publisher":"FIRST EPSS","observed_at":"2026-11-04T23:33:33.055Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 4.0.0, <= 5.8.0"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 3.3.0, <= 3.10.6"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 2.2.0, <= 2.4.6"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 2.0.0, <= 2.1.17"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["<= 1.30.5"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 4.0.0; fixed 5.8.1"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 3.3.0; fixed 3.10.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.2.0; fixed 2.4.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.1.18"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 1.30.6"]}],"null_published_at":"2026-11-06T07:24:11.240Z","source_updated_at":"2026-07-23T15:01:52.000Z","source_disclosed_at":"2026-07-23T15:01:50.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T21:42:51.445Z"},{"id":"NVI-00004730","kind":"vulnerability","title":"PHPSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-xh5m-36r6-47m3","CVE-2026-59933"],"plain_summary":"GitHub lists this reviewed advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 5.8.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 3.10.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.4.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.1.18 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 1.30.6 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-23T15:01:52.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-03e66163027143f55cc054719fff5fd0"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-03e66163027143f55cc054719fff5fd0","url":"https://github.com/advisories/GHSA-xh5m-36r6-47m3","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-xh5m-36r6-47m3","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T17:42:43.803Z"},{"id":"sr-70c7746745a03cfe10099faa8a013b95","url":"https://github.com/advisories/GHSA-xh5m-36r6-47m3","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-xh5m-36r6-47m3","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:51.445Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 4.0.0, <= 5.8.0"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 3.3.0, <= 3.10.6"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 2.2.0, <= 2.4.6"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":[">= 2.0.0, <= 2.1.17"]},{"certainty":"source_listed","source_ids":["sr-03e66163027143f55cc054719fff5fd0"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["<= 1.30.5"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 4.0.0; fixed 5.8.1"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 3.3.0; fixed 3.10.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.2.0; fixed 2.4.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.1.18"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 1.30.6"]}],"null_published_at":"2026-11-04T10:04:27.864Z","source_updated_at":"2026-07-23T15:01:52.000Z","source_disclosed_at":"2026-07-23T15:01:50.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:42:51.445Z"},{"id":"NVI-00004730","kind":"vulnerability","title":"PHPSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-xh5m-36r6-47m3","CVE-2026-59933"],"plain_summary":"OSV carries this publisher advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet. This is an aggregated source copy; consult the original publisher and compare update dates.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"The original advisory lists fixed boundaries 5.8.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 3.10.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.4.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.1.18 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 1.30.6 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-70c7746745a03cfe10099faa8a013b95","url":"https://github.com/advisories/GHSA-xh5m-36r6-47m3","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-xh5m-36r6-47m3","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:51.445Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 4.0.0; fixed 5.8.1"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 3.3.0; fixed 3.10.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.2.0; fixed 2.4.7"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.1.18"]},{"certainty":"source_listed","source_ids":["sr-70c7746745a03cfe10099faa8a013b95"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"## Summary\n\nPhpSpreadsheet's OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed `.xls`/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, `OLERead::read()` appends the same sector data repeatedly until the PHP process exhausts memory.\n\nThis is reachable from `Reader\\Xls::canRead()` and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file.\n\n## Vulnerability details\n\n`OLERead::read()` loads the input and builds sector chains from attacker-controlled OLE header and allocation-table values:\n\n- `src/PhpSpreadsheet/Shared/OLERead.php:82` reads the entire file after validating only the OLE magic.\n- `src/PhpSpreadsheet/Shared/OLERead.php:84-97` reads sector-chain metadata from the file header.\n- `src/PhpSpreadsheet/Shared/OLERead.php:132-146` builds `bigBlockChain` and then follows the small-block depot chain.\n\nThe vulnerable loop is:\n\n```php\n$sbdBlock = $this->sbdStartBlock;\n$this->smallBlockChain = '';\nwhile ($sbdBloc","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 1.30.6"]}],"null_published_at":"2026-10-31T22:12:57.140Z","source_updated_at":"2026-07-23T16:27:55.018Z","source_disclosed_at":"2026-07-23T15:01:50.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T21:42:51.445Z"}],"next_cursor":null,"snapshot_revision":"42594"}