{"items":[{"id":"NVI-00002167","kind":"vulnerability","title":"XXE in PHPSpreadsheet's XLSX reader","revision":3,"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-6hwr-6v2f-3m88","CVE-2024-45293"],"plain_summary":"OSV carries this publisher advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpexcel. 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 2.3.0 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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 1.29.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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 2.1.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-386d5888b4684a5504a1f6d4084ba243"],"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}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-06-17T07:53:58.013Z","value":"7.5 HIGH (3.1)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-aeefc38dfbdc55031d0de90409daedec"},{"kind":"CVSS","as_of":"2026-06-17T07:53:58.013Z","value":"7.5 HIGH (3.1)","meaning":"nvd@nist.gov severity; no combined Null risk score.","source_id":"sr-aeefc38dfbdc55031d0de90409daedec"},{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"2.776%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.86361. Missing scores are unknown.","source_id":"sr-386d5888b4684a5504a1f6d4084ba243"}],"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-0e2ff0dcdaae026b29689e08c13c0300","url":"https://github.com/advisories/GHSA-6hwr-6v2f-3m88","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-6hwr-6v2f-3m88","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:41:59.937Z"},{"id":"sr-aeefc38dfbdc55031d0de90409daedec","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-45293","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2024-45293","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-01T00:59:36.384Z"},{"id":"sr-386d5888b4684a5504a1f6d4084ba243","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-2024-45293","publisher":"FIRST EPSS","observed_at":"2026-10-31T22:06:15.368Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 2.2.0; fixed 2.3.0"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 1.29.1"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.1.1"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpexcel","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 0; last_affected 1.8.2"]}],"null_published_at":"2026-11-06T15:18:17.680Z","source_updated_at":"2025-03-06T18:36:55.798Z","source_disclosed_at":"2024-10-07T15:58:52.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:41:59.937Z"},{"id":"NVI-00002167","kind":"vulnerability","title":"XXE in PHPSpreadsheet's XLSX reader","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-6hwr-6v2f-3m88","CVE-2024-45293"],"plain_summary":"OSV carries this publisher advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpexcel. 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 2.3.0 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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 1.29.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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 2.1.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-386d5888b4684a5504a1f6d4084ba243"],"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}],"schema_version":"1.1.0","source_metrics":[{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"2.776%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.86361. Missing scores are unknown.","source_id":"sr-386d5888b4684a5504a1f6d4084ba243"}],"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-0e2ff0dcdaae026b29689e08c13c0300","url":"https://github.com/advisories/GHSA-6hwr-6v2f-3m88","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-6hwr-6v2f-3m88","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:41:59.937Z"},{"id":"sr-386d5888b4684a5504a1f6d4084ba243","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-2024-45293","publisher":"FIRST EPSS","observed_at":"2026-10-31T22:06:15.368Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 2.2.0; fixed 2.3.0"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 1.29.1"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.1.1"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpexcel","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 0; last_affected 1.8.2"]}],"null_published_at":"2026-10-31T22:27:15.292Z","source_updated_at":"2025-03-06T18:36:55.798Z","source_disclosed_at":"2024-10-07T15:58:52.000Z","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":"2026-10-31T21:41:59.937Z"},{"id":"NVI-00002167","kind":"vulnerability","title":"XXE in PHPSpreadsheet's XLSX reader","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-6hwr-6v2f-3m88","CVE-2024-45293"],"plain_summary":"OSV carries this publisher advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpexcel. 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 2.3.0 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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 1.29.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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 2.1.1 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"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-0e2ff0dcdaae026b29689e08c13c0300","url":"https://github.com/advisories/GHSA-6hwr-6v2f-3m88","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-6hwr-6v2f-3m88","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:41:59.937Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 2.2.0; fixed 2.3.0"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 1.29.1"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpspreadsheet","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.1.1"]},{"certainty":"source_listed","source_ids":["sr-0e2ff0dcdaae026b29689e08c13c0300"],"technology":"phpoffice/phpexcel","known_exclusions":[],"conditions_summary":"### Summary\nThe security scanner responsible for preventing XXE attacks in the XLSX reader can be bypassed by slightly modifying the XML structure, utilizing white-spaces. On servers that allow users to upload their own Excel (XLSX) sheets, Server files and sensitive information can be disclosed by providing a crafted sheet. \n\n### Details\nThe security scan function in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php` contains a flawed XML encoding check to retrieve the input file's XML encoding in the `toUtf8` function. \n\nThe function searches for the XML encoding through a defined regex which looks for `encoding=\"*\"` and/or `encoding='*'`, if not found, it defaults to the UTF-8 encoding which bypasses the conversion logic. \n\n ```\n$patterns = [\n            '/encoding=\"([^\"]*]?)\"/',\n            \"/encoding='([^']*?)'/\",\n];\n```\n\nThis logic can be used to pass a UTF-7 encoded XXE payload, by utilizing a whitespace before or after the `=` in the attribute definition. \n\n### PoC\n\nNeeded:\n- An Excel sheet (XLSX) with at least one cell containing a value.\n\nUnzip the excel sheet, and modify the `xl/SharedStrings.xml` file with the following value (note the space after `encoding=`):\n\n```\n<?","public_affected_ranges":["ECOSYSTEM: introduced 0; last_affected 1.8.2"]}],"null_published_at":"2026-10-31T21:54:04.899Z","source_updated_at":"2025-03-06T18:36:55.798Z","source_disclosed_at":"2024-10-07T15:58:52.000Z","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":"2026-10-31T21:41:59.937Z"}],"next_cursor":null,"snapshot_revision":"42594"}