CVE-2026-81963 Microsoft Windows Link Following

Exploited in the wild High 7.8 Published 8 Sep 2026 Updated 14 Oct 2026

An authorized local attacker can elevate privileges by exploiting improper link resolution in the Windows Update Stack.

Exploited in the wild: Since 8 Sep 2026
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-81963?

CVE-2026-81963 is a high-severity path traversal vulnerability in Microsoft Windows 11 23h2, published on 8 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.

Weakness: CWE-59, CWE-284

Which versions are affected by CVE-2026-81963?

It affects 5 products.

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

How do I fix CVE-2026-81963?

No fix has been published for CVE-2026-81963 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 22 Sep 2026.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-81963 being exploited?

Yes. Attackers have exploited CVE-2026-81963 in the wild since at least 8 Sep 2026.

Public exploit code: 1 proofs of concept on GitHub.

All Microsoft Windows 11 23h2 vulnerabilities

Sources

Also known as GHSA-4j4j-2wjq-mxqj.