CVE-2026-85804 Windows Win32 Kernel Subsystem Elevation of Privilege Vulnerability

High 7.8 Published Updated

An authorized local attacker can exploit a use-after-free flaw in the Windows Win32 Kernel Subsystem to elevate privileges.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-85804?

CVE-2026-85804 is a high-severity use after free vulnerability in Microsoft Windows 11 23h2, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Use after free in Windows Win32 Kernel Subsystem allows an authorized attacker to elevate privileges locally.

Weakness: CWE-416

Which versions are affected by CVE-2026-85804?

It affects 6 products.

Products include Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows 11 26h2, Microsoft Windows Server 2025.

How do I fix CVE-2026-85804?

No fix has been published for CVE-2026-85804 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2026-85804 being exploited?

There is no known exploitation of CVE-2026-85804 in the wild and no public exploit code.

All Microsoft Windows 11 23h2 vulnerabilities

Sources

Also known as GHSA-x8w7-p4pj-rvm5.

Is CVE-2026-85804 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free