---
id: CVE-2026-113351
title: libexpat 2.7.2 through 2.9.0 Denial of Service via XML_ParserReset
summary: >-
  libexpat 2.7.2 through 2.9.0 contains a denial of service vulnerability
  because XML_ParserReset zeroes the direct byte count but never offsets tracked
  heap allocations. Attackers can submit a large XML document so later documents
  on the …
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-909
  - CWE-459
vendor: libexpat
product: libexpat
affected:
  - libexpat >= 2.7.2 <= 2.9.0
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-20T15:10:35.530839Z'
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T16:06:48.218Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-113351'
references:
  - url: 'https://github.com/libexpat/libexpat/pull/1431'
  - url: >-
      https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L860-L884
  - url: >-
      https://github.com/libexpat/libexpat/blob/a76b1174c1ea52abb639a4c69d52b630a8a106a2/expat/lib/xmlparse.c#L1560
  - url: 'https://github.com/libexpat/libexpat'
  - url: >-
      https://www.vulncheck.com/advisories/libexpat-2.7.2-through-2.9.0-denial-of-service-via-xml-parserreset
    label: >-
      VulnCheck Advisory: libexpat 2.7.2 through 2.9.0 Denial of Service via
      XML_ParserReset
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-113351.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-113351'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2556110'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-113351'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-113351'
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-10-20T12:05:07.320Z'
epss: 0.00474
epssPercentile: 0.40787
---

## Overview

libexpat 2.7.2 through 2.9.0 contains a denial of service vulnerability because XML_ParserReset zeroes the direct byte count but never offsets tracked heap allocations. Attackers can submit a large XML document so later documents on the same reset parser fail with XML_ERROR_NO_MEMORY until it is recreated.

## Affected

- `libexpat >= 2.7.2 <= 2.9.0`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat Hardened Images, … · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-113351.json)