Use After Free Affecting expat package, versions <2.8.2-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.18% (7th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-EXPAT-17496012
  • published25 Jun 2026
  • disclosed19 Jun 2026

Introduced: 19 Jun 2026

CVE-2026-56131  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Chainguard expat to version 2.8.2-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream expat package and not the expat package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).

CVSS Base Scores

version 3.1