{"id":"CVE-2026-21241","published":"2026-02-10T17:51:45Z","modified":"2026-08-19T16:26:14Z","title":"Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability","vendor":"Microsoft","product":"Windows 11 version 22H3","tier":"tail","description":{"text":"Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.","provenance":"source","from":"CVE.org"},"cvss":{"score":7,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.02602,"percentile":0.85301,"provenance":"source"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21241","tags":["vendor-advisory","patch"]}],"priority":{"score":22.0,"factors":[{"name":"EPSS percentile","points":17.06},{"name":"CVSS severity","points":4.9}]},"vendorSlug":"microsoft","affectedVersions":[{"vendor":"Microsoft","product":"Windows 11 version 22H3","versions":[">= 10.0.22631.0, < 10.0.22631.6649"]},{"vendor":"Microsoft","product":"Windows 11 Version 23H2","versions":[">= 10.0.22631.0, < 10.0.22631.6649"]},{"vendor":"Microsoft","product":"Windows 11 Version 24H2","versions":[">= 10.0.26100.0, < 10.0.26100.7840"]},{"vendor":"Microsoft","product":"Windows 11 Version 25H2","versions":[">= 10.0.26200.0, < 10.0.26200.7840"]},{"vendor":"Microsoft","product":"Windows 11 version 26H1","versions":[">= 10.0.28000.0, < 10.0.28000.1575"]},{"vendor":"Microsoft","product":"Windows 11 Version 26H1","versions":[">= 10.0.28000.0, < 10.0.28000.1575"]},{"vendor":"Microsoft","product":"Windows Server 2022","versions":[">= 10.0.20348.0, < 10.0.20348.4773"]},{"vendor":"Microsoft","product":"Windows Server 2022, 23H2 Edition (Server Core installation)","versions":[">= 10.0.25398.0, < 10.0.25398.2149"]},{"vendor":"Microsoft","product":"Windows Server 2025","versions":[">= 10.0.26100.0, < 10.0.26100.32370"]},{"vendor":"Microsoft","product":"Windows Server 2025 (Server Core installation)","versions":[">= 10.0.26100.0, < 10.0.26100.32370"]}],"euvd":{"id":"EUVD-2026-7319","exploited":false,"provenance":"source"},"lineage":{"familyId":"fam-class-microsoft-windows-cwe-416"}}