---
id: CVE-2026-108357
title: >-
  PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows
  XXE and Denial of Service
summary: >-
  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::trySimpleXMLLoadStringPrivat…
severity: high
cvss: 8.8
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:L/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-611
  - CWE-776
vendor: PHPOffice
product: PhpSpreadsheet
affected:
  - 'PhpSpreadsheet >= 3.3.0, < 3.10.8'
  - 'PhpSpreadsheet >= 4.0.0, < 5.10.0'
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T17:38:16.098Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-108357'
references:
  - url: >-
      https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc
    label: >-
      https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc
  - url: >-
      https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781
    label: >-
      https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781
  - url: >-
      https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738
    label: >-
      https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738
  - url: 'https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8'
    label: 'https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8'
  - url: 'https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0'
    label: 'https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0'
tags:
  - cve.org
ingestedAt: '2026-10-22T22:00:50.356Z'
---

## Overview

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.

## Affected

- `PhpSpreadsheet >= 3.3.0, < 3.10.8`
- `PhpSpreadsheet >= 4.0.0, < 5.10.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.