CVE-2026-93689

EUVD-2026-82985
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.5 MEDIUM
LOCAL
LOW
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Common Weakness Enumeration
References
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