CVE-2026-69617 Windows Resilient File System (ReFS) Elevation of Privilege Vulnerability

High 7.0 Published 8 Sep 2026 Updated 14 Oct 2026

An out-of-bounds read in the Windows ReFS 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-2026-69617?

CVE-2026-69617 is a high-severity memory corruption vulnerability in Microsoft Windows 11 26h1, 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

Out-of-bounds read in Windows Resilient File System (ReFS) allows an authorized attacker to elevate privileges locally.

Weakness: CWE-125

Which versions are affected by CVE-2026-69617?

It affects 2 products.

Products include Microsoft Windows 11 26h1, Microsoft Windows Server 2025.

How do I fix CVE-2026-69617?

No fix has been published for CVE-2026-69617 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-2026-69617 being exploited?

There is no known exploitation of CVE-2026-69617 in the wild and no public exploit code.

All Microsoft Windows 11 26h1 vulnerabilities

Sources

Also known as GHSA-q363-37w8-7887.