CVE-2026-69621 Role: Windows Fax Service Elevation of Privilege Vulnerability

High 7.0 Published Updated

A heap-based buffer overflow in the Windows Fax Service allows an authorized 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-2026-69621?

CVE-2026-69621 is a high-severity memory corruption 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

Heap-based buffer overflow in Windows Fax Service allows an authorized attacker to elevate privileges locally.

Weakness: CWE-122

Which versions are affected by CVE-2026-69621?

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-2026-69621?

No fix has been published for CVE-2026-69621 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-69621 being exploited?

There is no known exploitation of CVE-2026-69621 in the wild and no public exploit code.

All Microsoft Windows 10 1607 vulnerabilities

Sources

Also known as GHSA-9rch-hmj9-5v86.

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