{"id":"CVE-2026-20820","published":"2026-01-13T17:56:15Z","modified":"2026-07-30T20:46:33Z","title":"Windows Common Log File System Driver Elevation of Privilege Vulnerability","vendor":"Microsoft","product":"Windows 10 Version 1607","tier":"tail","description":{"text":"Heap-based buffer overflow in Windows Common Log File System Driver allows an authorized attacker to elevate privileges locally.","provenance":"source","from":"CVE.org"},"cvss":{"score":7.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/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":0.02564,"percentile":0.85059,"provenance":"source"},"cwes":[{"id":"CWE-122","name":"Heap-based Buffer Overflow"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20820","tags":["vendor-advisory","patch"]}],"priority":{"score":22.5,"factors":[{"name":"EPSS percentile","points":17.01},{"name":"CVSS severity","points":5.46}]},"vendorSlug":"microsoft","affectedVersions":[{"vendor":"Microsoft","product":"Windows 10 Version 1607","versions":[">= 10.0.14393.0, < 10.0.14393.8783"]},{"vendor":"Microsoft","product":"Windows 10 Version 1809","versions":[">= 10.0.17763.0, < 10.0.17763.8276"]},{"vendor":"Microsoft","product":"Windows 10 Version 21H2","versions":[">= 10.0.19044.0, < 10.0.19044.6809"]},{"vendor":"Microsoft","product":"Windows 10 Version 22H2","versions":[">= 10.0.19045.0, < 10.0.19045.6809"]},{"vendor":"Microsoft","product":"Windows 11 version 23H2","versions":[">= 10.0.22631.0, < 10.0.22631.6491"]},{"vendor":"Microsoft","product":"Windows 11 Version 23H2","versions":[">= 10.0.22631.0, < 10.0.22631.6491"]},{"vendor":"Microsoft","product":"Windows 11 Version 24H2","versions":[">= 10.0.26100.0, < 10.0.26100.7623"]},{"vendor":"Microsoft","product":"Windows 11 Version 25H2","versions":[">= 10.0.26200.0, < 10.0.26200.7623"]},{"vendor":"Microsoft","product":"Windows Server 2008 R2 Service Pack 1","versions":[">= 6.1.7601.0, < 6.1.7601.28117"]},{"vendor":"Microsoft","product":"Windows Server 2008 R2 Service Pack 1 (Server Core installation)","versions":[">= 6.1.7601.0, < 6.1.7601.28117"]}],"euvd":{"id":"EUVD-2026-2211","exploited":false,"provenance":"source"},"lineage":{"familyId":"fam-class-microsoft-windows-cwe-122"}}