Double free in Microsoft Windows - CVE-2026-85921
Published: September 17, 2026
Vulnerability identifier: #VU150712
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-85921
CWE-ID: CWE-415
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to elevate privileges.
The vulnerability exists due to a double free in Windows Secure Kernel Mode when exploiting the secure kernel locally. A local privileged user can trigger the double free to elevate privileges.
Successful exploitation can result in Virtual Trust Level 1 (VTL1) privileges.
Affected software
Microsoft Windows
How to mitigate CVE-2026-85921
Install security update from vendor's website.
Microsoft Windows - update to 11 26H1 10.0.28000.2956