CVE-2026-20838 Windows Kernel Information Disclosure Vulnerability

Medium 5.5 Published 13 Jan 2026 Updated 30 Jul 2026

An authorized local attacker can exploit a Windows Kernel error message generation flaw to disclose sensitive information.

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-2026-20838?

CVE-2026-20838 is a medium-severity vulnerability in Microsoft Windows 11 23h2, published on 13 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Generation of error message containing sensitive information in Windows Kernel allows an authorized attacker to disclose information locally.

Weakness: CWE-209

Which versions are affected by CVE-2026-20838?

It affects 6 products.

Products include Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows Server 2022, Microsoft Windows Server 2022 23h2, Microsoft Windows Server 2025.

How do I fix CVE-2026-20838?

No fix has been published for CVE-2026-20838 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-20838 being exploited?

There is no known exploitation of CVE-2026-20838 in the wild and no public exploit code.

All Microsoft Windows 11 23h2 vulnerabilities

Sources

Also known as GHSA-6j3g-2jh3-q8rg.