CVE-2026-93689
Severity CVSS v4.0:
MEDIUM
Type:
CWE-476
NULL Pointer Dereference
Publication date:
18/09/2026
Last modified:
22/09/2026
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.
Impact
Base Score 4.0
6.80
Severity 4.0
MEDIUM
Base Score 3.x
5.50
Severity 3.x
MEDIUM
References to Advisories, Solutions, and Tools
- https://github.com/winfsp/winfsp
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L105-L114
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L146-L152
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L68-L73
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/volume.c#L1059-L1060
- https://github.com/winfsp/winfsp/commit/b8103265ec63fa87ac264c62bb796dbc38376652
- https://github.com/winfsp/winfsp/releases/tag/v2.2B4
- https://www.vulncheck.com/advisories/winfsp-through-2.2.26215-null-pointer-dereference-via-fast-i-o


