{"id":"CVE-2026-93689","title":"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","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 se…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"winfsp","product":"winfsp","affected":["winfsp <= 2.2.26215"],"published":"2026-09-18","updated":"2026-09-18","sourceUpdated":"2026-09-18T17:17:07.437","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93689","references":[{"url":"https://github.com/winfsp/winfsp","label":"disclosure@vulncheck.com"},{"url":"https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L105-L114","label":"disclosure@vulncheck.com"},{"url":"https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L146-L152","label":"disclosure@vulncheck.com"},{"url":"https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L68-L73","label":"disclosure@vulncheck.com"},{"url":"https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/volume.c#L1059-L1060","label":"disclosure@vulncheck.com"},{"url":"https://github.com/winfsp/winfsp/commit/b8103265ec63fa87ac264c62bb796dbc38376652","label":"disclosure@vulncheck.com"},{"url":"https://github.com/winfsp/winfsp/releases/tag/v2.2B4","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/winfsp-through-2.2.26215-null-pointer-dereference-via-fast-i-o","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-18T16:18:34.054641Z"},"ingestedAt":"2026-09-18T15:44:31.587Z","epss":0.00116,"epssPercentile":0.01847,"slug":"CVE-2026-93689","body":"## Overview\n\nWinFsp 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}