CVE-2026-93689 WinFsp through 2.2.26215 NULL Pointer Dereference via Fast I/O
An unprivileged local user can cause a system crash by triggering a null pointer dereference in the WinFsp kernel driver's Fast I/O handler.
- 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-2026-93689?
CVE-2026-93689 is a medium-severity vulnerability in winfsp, published on 18 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
WinFsp through 2.2.26215 contains a null pointer dereference vulnerability in the kernel driver's Fast I/O device control handler that fails to validate the volume context before use. An unprivileged local user can trigger a denial of service by opening the WinFsp control device and issuing FSP_IOCTL_TRANSACT requests, causing a system crash.
Weakness: CWE-476
Which versions are affected by CVE-2026-93689?
How do I fix CVE-2026-93689?
No fix has been published for CVE-2026-93689 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-93689 being exploited?
There is no known exploitation of CVE-2026-93689 in the wild and no public exploit code.
Sources
Also known as GHSA-grx3-v6wv-8gq8.