CVE-2025-26687 Win32k Elevation of Privilege Vulnerability

High 7.5 Published 8 Apr 2025 Updated 10 Aug 2026

An attacker can exploit a use-after-free flaw in Windows Win32K to elevate privileges over a network.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2025-26687?

CVE-2025-26687 is a high-severity use after free vulnerability in Microsoft 365 Copilot, published on 8 Apr 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Use after free in Windows Win32K - GRFX allows an unauthorized attacker to elevate privileges over a network.

Weakness: CWE-416

Which versions are affected by CVE-2025-26687?

It affects 17 products.

Products include Microsoft 365 Copilot, Microsoft Office, Microsoft Windows 10 1507, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2 and 11 more.

How do I fix CVE-2025-26687?

No fix has been published for CVE-2025-26687 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2025-26687 being exploited?

There is no known exploitation of CVE-2025-26687 in the wild and no public exploit code.

All Microsoft 365 Copilot vulnerabilities

Sources

Also known as GHSA-p9qw-h5h2-6vw8.