WinFsp through 2.2.26215 NULL Pointer Dereference via Fast I/O
Historical advisory recorded 23 Oct 2026 15:48:27 UTC. Read the latest advisory.
cve-program · CVE-2026-93689
PublishedWinFsp 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.
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CVE-2026-93689 · CVE overview and exploitation status
cve-program · CVE-2026-93689
- https://github.com/winfsp/winfsp/commit/b8103265ec63fa87ac264c62bb796dbc38376652
- https://github.com/winfsp/winfsp
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L68-L73
- 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/volume.c#L1059-L1060
- 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
This historical advisory does not include today's related changes. Open the latest advisory to find current connections.