CVE-2026-93689 json
WinFsp through 2.2.26215 NULL Pointer Dereference via Fast I/O
published 2026-09-18 51 d ago modified 2026-09-24 46 d ago also EUVD-2026-82985
- cvss
- 5.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 4%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 51 d ago
Exploit prediction
0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.8 | 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 |
| CNA | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 6.8 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- winfsp winfsp
Classification
- Weakness
-
- CWE-476 NULL Pointer Dereference
References
-
github.com
/winfsp/winfsp/commit/b8103265ec63fa87ac264c62bb796dbc38376652
patch
-
github.com
/winfsp/winfsp
product
-
github.com
/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L68-L73
technical-description
-
github.com
/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L105-L114
technical-description
-
github.com
/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L146-L152
technical-description
-
github.com
/winfsp/winfsp/blob/v2.2B4/src/sys/volume.c#L1059-L1060
technical-description
-
github.com
/winfsp/winfsp/releases/tag/v2.2B4
release-notes
-
vulncheck.com
/advisories/winfsp-through-2.2.26215-null-pointer-dereference-via-fast-i-o
third-party-advisory
Sources
- CVE List CVE-2026-93689
- NVD CVE-2026-93689
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