What is CVE-2026-85091?

CVE-2026-85091 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. zlib 1.3.1.2 through 1.3.2 Heap Buffer Overflow via gz_vacate

Which CVE IDs does CVE-2026-85091 cover?

CVE-2026-85091 covers the following CVE IDs: CVE-2026-85091. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-85091?

CVE-2026-85091 has a CVSS v3 base score of 7.4, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-85091?

CVE-2026-85091 affects 5 products, including: azl3 cloud-hypervisor 52.0.152-1 on Azure Linux 3.0; azl3 kata-containers 3.32.0.kata0-2 on Azure Linux 3.0; azl3 kata-containers 3.32.0.kata0-5 on Azure Linux 3.0; azl3 kata-containers 4.1.0.kata0-1 on Azure Linux 3.0; azl3 zlib 1.3.2-1 on Azure Linux 3.0.

CVE-2026-85091HighCVSS 7.4

zlib 1.3.1.2 through 1.3.2 Heap Buffer Overflow via gz_vacate

Vendor

Microsoft Security Response Center (MSRC)

Published

September 11, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-85091 →

🎯 Affected products5

azl3 cloud-hypervisor 52.0.152-1 on Azure Linux 3.0
azl3 kata-containers 3.32.0.kata0-2 on Azure Linux 3.0
azl3 kata-containers 3.32.0.kata0-5 on Azure Linux 3.0
azl3 kata-containers 4.1.0.kata0-1 on Azure Linux 3.0
azl3 zlib 1.3.2-1 on Azure Linux 3.0

✅ Remediation

KBRelease Notes (Security Update) KBRelease Notes (Security Update) — fixed build 1.3.2-2 Security Update

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85091
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade