What is CVE-2026-19666?

CVE-2026-19666 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. Use-after-free in query_addnoqnameproof() via the DNS64 filter64 path

Which CVE IDs does CVE-2026-19666 cover?

CVE-2026-19666 covers the following CVE IDs: CVE-2026-19666. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-19666?

CVE-2026-19666 has a CVSS v3 base score of 7.5, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-19666?

CVE-2026-19666 affects 1 product, including: azl3 bind 9.20.26-1 on Azure Linux 3.0.

CVE-2026-19666HighCVSS 7.5

Use-after-free in query_addnoqnameproof() via the DNS64 filter64 path

Vendor

Microsoft Security Response Center (MSRC)

Published

September 21, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-19666 →

🎯 Affected products1

azl3 bind 9.20.26-1 on Azure Linux 3.0

✅ Remediation

KBRelease Notes (Security Update)

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-19666
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade