What is CVE-2026-4177?

CVE-2026-4177 is a security advisory published by Microsoft Security Response Center (MSRC) with Critical severity. YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter

Which CVE IDs does CVE-2026-4177 cover?

CVE-2026-4177 covers the following CVE IDs: CVE-2026-4177. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-4177?

CVE-2026-4177 has a CVSS v3 base score of 9.1, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-4177?

CVE-2026-4177 affects 1 product, including: azl3 perl-YAML 1.30-2 on Azure Linux 3.0.

CVE-2026-4177CriticalCVSS 9.1

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter

Vendor

Microsoft Security Response Center (MSRC)

Published

October 21, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-4177 →

🎯 Affected products1

azl3 perl-YAML 1.30-2 on Azure Linux 3.0

✅ Remediation

KBRelease Notes (Security Update)

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-4177
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade