CVE-2026-20821 Remote Procedure Call Information Disclosure Vulnerability

Medium 6.2 Published Updated

An unauthorized local attacker can exploit a flaw in Windows Remote Procedure Call to disclose sensitive information.

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

What is CVE-2026-20821?

CVE-2026-20821 is a medium-severity vulnerability in Microsoft Windows 10 1607, 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

Exposure of sensitive information to an unauthorized actor in Windows Remote Procedure Call allows an unauthorized attacker to disclose information locally.

Weakness: CWE-200

Which versions are affected by CVE-2026-20821?

It affects 14 products.

Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2 and 8 more.

How do I fix CVE-2026-20821?

No fix has been published for CVE-2026-20821 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-20821 being exploited?

There is no known exploitation of CVE-2026-20821 in the wild and no public exploit code.

All Microsoft Windows 10 1607 vulnerabilities

Sources

Also known as GHSA-5hhg-fcqc-m87m.

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