vulnerability / NVI-00005133 / Revision 4
PhpSpreadsheet: XmlScanner Bypass via ISO-2022 Escape Sequences Allows XXE and Denial of Service
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.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
8.8 HIGH (4.0)
security-advisories@github.com severity; no combined Null risk score.
0.625%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.50104. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
phpoffice/phpspreadsheet
source listed>= 4.0.0, <= 5.9.0
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listed>= 3.3.0, <= 3.10.7
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listed>= 2.2.0, <= 2.4.7
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listed>= 2.0.0, <= 2.1.18
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listed<= 1.30.6
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 4.0.0; fixed 5.10.0
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 3.3.0; fixed 3.10.8
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 2.2.0; fixed 2.4.8
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 2.0.0; fixed 2.1.19
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 0; fixed 1.30.7
### Summary PhpSpreadsheet's `XmlScanner::scan()` uses a regex pattern that only accounts for NULL byte (0x00) interleaving when detecting `<!DOCTYPE`. ISO-2022 escape sequences (0x1B bytes) inserted between the characters of the pattern break the regex match entirely, allowing DOCTYPE declarations with entity definitions to pass through undetected. This enables Denial of Service via quadratic entity expansion on **all PHP versions**, and XXE/SSRF on PHP < 8.0 or when `LIBXML_NOENT` is used. Any application using PhpSpreadsheet to process user-uploaded XLSX files is affected. ### Details The vulnerability exists in `src/PhpSpreadsheet/Reader/Security/XmlScanner.php`, method `scan()`, lines 87–100. The scanner builds a regex pattern `/\0*<\0*!\0*D\0*O\0*C\0*T\0*Y\0*P\0*E\0*/` that only handles NULL byte interleaving. ISO-2022 escape sequences (e.g., `0x1B 0x28 0x42` for ISO-2022-JP) inserted between each character of `<!DOCTYPE` break the regex because it only expects optional `\0` between characters. The XLSX reader extracts XML parts from the ZIP archive and passes each through `XmlScanner::scan()` before `simplexml_load_string()`. The XML parser strips the ESC bytes during cha
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
- vendor patch
The original advisory lists fixed boundaries 5.10.0 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 3.10.8 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 2.4.8 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 2.1.19 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 1.30.7 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-3x94-m842-937c ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- GHSA-3x94-m842-937c ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-108358 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2026-108358 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 4 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.