CVE-2026-20833 Windows Kerberos Information Disclosure Vulnerability

Medium 5.5 Published Updated

An authorized local attacker can exploit weak Kerberos cryptography to disclose sensitive information on Windows Server systems.

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-2026-20833?

CVE-2026-20833 is a medium-severity vulnerability in Microsoft Windows Server 2008, 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

Use of a broken or risky cryptographic algorithm in Windows Kerberos allows an authorized attacker to disclose information locally.

Weakness: CWE-327

Which versions are affected by CVE-2026-20833?

It affects 7 products.

Products include Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2022 23h2 and 1 more.

How do I fix CVE-2026-20833?

No fix has been published for CVE-2026-20833 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-20833 being exploited?

There is no known exploitation of CVE-2026-20833 in the wild and no public exploit code.

Public exploit code: 2 proofs of concept on GitHub.

All Microsoft Windows Server 2008 vulnerabilities

Sources

Also known as GHSA-qvf8-2q87-3fcr.

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