CVE-2026-93689

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.

Affected Platforms

Weakness Type

CWE-476

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