What is CVE-2026-56409?

CVE-2026-56409 is a security advisory published by Microsoft Security Response Center (MSRC) with Medium severity. xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.

Which CVE IDs does CVE-2026-56409 cover?

CVE-2026-56409 covers the following CVE IDs: CVE-2026-56409. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-56409?

CVE-2026-56409 has a CVSS v3 base score of 6.5, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-56409?

CVE-2026-56409 affects 1 product, including: azl3 expat 2.6.4-6 on Azure Linux 3.0.

CVE-2026-56409MediumCVSS 6.5

xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.

Vendor

Microsoft Security Response Center (MSRC)

Published

June 30, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-56409 →

🎯 Affected products1

azl3 expat 2.6.4-6 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-2026-56409
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade