CVE-2026-69421 Windows Kernel-Mode Driver Elevation of Privilege Vulnerability

High 7.8 Published Updated

An integer underflow in the Windows Kernel Mode Driver allows a local attacker to elevate privileges.

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-2026-69421?

CVE-2026-69421 is a high-severity vulnerability in Microsoft Windows 10 1607, 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

Integer underflow (wrap or wraparound) in Windows Kernel Mode Driver allows an authorized attacker to elevate privileges locally.

Weakness: CWE-191, CWE-122

Which versions are affected by CVE-2026-69421?

It affects 13 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 7 more.

How do I fix CVE-2026-69421?

No fix has been published for CVE-2026-69421 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-69421 being exploited?

There is no known exploitation of CVE-2026-69421 in the wild and no public exploit code.

All Microsoft Windows 10 1607 vulnerabilities

Sources

Also known as GHSA-8rj7-6qp9-5fmj.

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