What is CVE-2026-85921?

CVE-2026-85921 is a high-severity vulnerability in Microsoft Windows 11 Version 26h1, classified under Double Free. CVSS score: 8.2/10. Published 2026-09-14.

How severe is CVE-2026-85921?

High severity. CVSS v3 base score is 8.2 out of 10.

Double Free in Microsoft Windows 11 Version 26h1

CVE-2026-85921

Double free in Windows Secure Kernel Mode allows an authorized attacker to elevate privileges locally.

Vulnerability class: Double Free

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

Affected products

Microsoft Windows 11 Version 26h1

Weakness classification (CWE)

CWE-415 — Double Free

References

secure@microsoft.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-85921?: CVE-2026-85921 is a high-severity vulnerability in Microsoft Windows 11 Version 26h1, classified under Double Free. CVSS score: 8.2/10. Published 2026-09-14.
How severe is CVE-2026-85921?: High severity. CVSS v3 base score is 8.2 out of 10.