CVE-2026-20939 Windows File Explorer Information Disclosure Vulnerability

Medium 5.5 Published Updated

An authorized local attacker can exploit Windows File Explorer to disclose sensitive information to unauthorized actors.

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-2026-20939?

CVE-2026-20939 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 File Explorer allows an authorized attacker to disclose information locally.

Weakness: CWE-200

Which versions are affected by CVE-2026-20939?

It affects 12 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 6 more.

How do I fix CVE-2026-20939?

No fix has been published for CVE-2026-20939 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-20939 being exploited?

There is no known exploitation of CVE-2026-20939 in the wild and no public exploit code.

All Microsoft Windows 10 1607 vulnerabilities

Sources

Also known as GHSA-x6j9-355w-c9c4.

Is CVE-2026-20939 in your software?

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

Check your SBOMs for free