CVE-2026-93689
MEDIUMCVSS 5.5Description
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.
Timeline
Published:September 18th, 2026 4:17 PM
Last modified:September 22nd, 2026 8:25 PM
CVSS Scoring
CVSS v3: 5.5 (MEDIUM)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weaknesses (CWE)
References & Reports
Advisories, patches, and third-party reports
- 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
Source: NIST NVD · Data may lag official sources by up to one minute