Windows Secure Kernel Mode Elevation of Privilege Vulnerability

CVE-2026-85921 is an elevation of privilege vulnerability in Windows Secure Kernel Mode (rated Critical, CVSS 8.2).

1 version

Microsoft id: CVE-2026-85921
Products: Windows Secure Kernel Mode
Severity: Critical
Impact: Elevation of Privilege
CVSS: 8.2
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
Exploited: No
Publicly disclosed: No
Exploitability: Exploitation Less Likely
Customer action required: Yes
Release: 2026-Sep
Assigned by: Microsoft
Weakness: CWE-415: Double Free
MSRC revision: 1.2
First captured by us: 13 Nov 2026, 16:00 UTC (from our first import of this list)
Microsoft last modified: 27 Sep 2026, 14:00 UTC
Source: Security updates · open the original at Microsoft

Microsoft's revision notes

Revision 1.0, 2026-09-14: Information published.
Revision 1.1, 2026-09-25: Updated an acknowledgement. This is an informational change only.
Revision 1.2, 2026-09-27: Acknowledgement Updated

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

Security updates, 14:00 UTC, 27 Sep

One version so far. If Microsoft edits it, each change shows here with what was removed and added.

First version we captured · 16:00 UTC, 13 Nov
The text as we first saw it
Seen by us 16:00 UTC, 13 Nov · Microsoft's timestamp 14:00 UTC, 27 Sep · Microsoft's page

Last updated 13 Nov 2026, 16:00 UTC