CVE-2026-93689
WinFsp through 2.2.26215 NULL Pointer Dereference via Fast I/O
- State
- Published
- Severity
- 6.8 Medium
- Published
- Sep 18, 2026
- Updated
- Sep 24, 2026
- Reserved
- Sep 18, 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.8 Medium | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 5.5 Medium | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
- CWE-476 NULL Pointer Dereference
Affected Products
| Product | Versions |
|---|---|
winfspwinfsp |
|
References
- Patch Commitpatch
- https://github.com/winfsp/winfspproduct
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L68-L73technical-description
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L105-L114technical-description
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L146-L152technical-description
- https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/volume.c#L1059-L1060technical-description
- winfsp v2.2B4 Release Notesrelease-notes
- VulnCheck Advisory: WinFsp through 2.2.26215 NULL Pointer Dereference via Fast I/Othird-party-advisory
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