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).

🔗 CVE IDs covered (1)

🎯 Affected products3

• azl3 cmake 3.30.3-13 on Azure Linux 3.0
• azl3 expat 2.6.4-6 on Azure Linux 3.0
• azl3 python3 3.12.9-11 on Azure Linux 3.0

✅ Remediation

KBCBL-Mariner Releases (Security Update) — fixed build 2.8.2-1

🔗 References (2)

• advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56131
• referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade