Overview
What is CVE-2026-56131?
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).
Vulnerability intelligence
CVE-2026-56131 and is rated Medium severity with a CVSS score of 4.9. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
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).