PhpSpreadsheet XML scanner bypass allows XXE and denial of service
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
PhpSpreadsheet from 3.3.0 before 3.10.8 and from 4.0.0 before 5.10.0 is affected. The XML reader decodes numeric entities only after its DOCTYPE checks, so a double-encoded less-than character lets an unchecked DOCTYPE and entity declaration reach the parser (CWE-611). An unauthenticated remote attacker who supplies crafted SpreadsheetML XML can cause entity-expansion denial of service, and on PHP before 8.0 or when LIBXML_NOENT is enabled can also read local files or perform SSRF.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| PHPOffice | PhpSpreadsheet | 3.3.0 to before 3.10.8; 4.0.0 to before 5.10.0 | 3.10.8, 5.10.0 | Patch available | CNA |
| — | phpoffice/phpspreadsheet (Packagist) | 4.0.0 to before 5.10.0 | 5.10.0 | Patch available | GHSA-rxj4-h86g-25gc |
| — | phpoffice/phpspreadsheet (Packagist) | 3.3.0 to before 3.10.8 | 3.10.8 | Patch available | GHSA-rxj4-h86g-25gc |
- PhpSpreadsheet VendorPHPOffice Affected 3.3.0 to before 3.10.8; 4.0.0 to before 5.10.0 Fixed in 3.10.8, 5.10.0 Patch available CNA
- phpoffice/phpspreadsheet (Packagist) Vendor— Affected 4.0.0 to before 5.10.0 Fixed in 5.10.0 Patch available GHSA-rxj4-h86g-25gc
- phpoffice/phpspreadsheet (Packagist) Vendor— Affected 3.3.0 to before 3.10.8 Fixed in 3.10.8 Patch available GHSA-rxj4-h86g-25gc
Remediation
Upgrade phpoffice/phpspreadsheet to 3.10.8 on the 3.x line or to 5.10.0 on the 5.x line.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA PhpSpreadsheet (PHPOffice) Fixed in 3.10.8, 5.10.0
- Fix · GHSA-rxj4-h86g-25gc phpoffice/phpspreadsheet (Packagist) Fixed in 5.10.0 Advisory →
- Fix · GHSA-rxj4-h86g-25gc phpoffice/phpspreadsheet (Packagist) Fixed in 3.10.8 Advisory →
Timeline
- 2026-10-22 Threatist record created from CVE-2026-108357
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-10-24 CISA SSVC decision points changed
- 2026-10-24 Priority changed: LOW → MEDIUM
- 2026-10-27 Alias added: GHSA-rxj4-h86g-25gc
References
Other 6
- https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc
- https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781
- https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738
- 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
More PHPOffice vulnerabilities
- TI-2026-32885 PhpSpreadsheet: File::prohibitWrappers bypass CVSS 4.0CRITICAL 9.2
- TI-2026-26406 PhpSpreadsheet SSRF and RCE via PHP stream wrappers in IOFactory::load CVSS 4.0CRITICAL 9.2
- TI-2026-79412 PhpSpreadsheet ODS reader exhausts CPU and memory via repeated rows CVSS 4.0HIGH 8.7
- TI-2025-34182 PhpSpreadsheet vulnerable to SSRF when reading and displaying a processed HTML document in the browser CVSS 4.0HIGH 8.7
- TI-2026-78784 Insecure deserialization in PHPOffice PHPPresentation allows code execution CVSS 4.0CRITICAL 9.2
- TI-2024-37339 PhpSpreadsheet vulnerable to unauthorized reflected XSS in Currency.php file CVSS 4.0HIGH 8.3
Sources
- CVE-2026-108357 · CVE Program
- CVE-2026-108357 · NVD
- FIRST EPSS
- GHSA-rxj4-h86g-25gc · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences