Vulnerability Description
PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. From 3.3.0 until 3.10.8 and 5.10.0, Reader\Xml passes stored SpreadsheetML XML through XmlScanner::scan in Xml::canRead and Xml::trySimpleXMLLoadStringPrivate, while Xml::unentity decodes numeric entities only after each DOCTYPE pattern check. A double-encoded less-than character is reduced by the first callback to another encoded character and by the second callback to a literal less-than sign, so SimpleXML receives an unchecked DOCTYPE and entity declaration. Processing attacker-controlled SpreadsheetML XML can cause entity-expansion denial of service and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 3.10.8 and 5.10.0.
Related Weaknesses (CWE)
References
- https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce2
- https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0
- https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-2
FAQ
What is CVE-2026-108357?
CVE-2026-108357 is a documented vulnerability. PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. From 3.3.0 until 3.10.8 and 5.10.0, Reader\Xml passes stored SpreadsheetML XML through XmlScanner::scan in Xml::canRead ...
How severe is CVE-2026-108357?
CVSS scoring is not yet available for CVE-2026-108357. Check NVD for updates.
Is there a patch for CVE-2026-108357?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.