{"id":"CVE-2026-83999","aliases":["EUVD-2026-73362","GHSA-wwcf-37pw-hpqr"],"status":"published","title":"Windows Resilient File System (ReFS) Deduplication Service Elevation of Privilege Vulnerability","description":"Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","severity":{"version":"3.1","score":7,"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00283,"percentile":0.21054,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-59"],"published":"2026-09-08T17:14:19Z","modified":"2026-11-10T21:33:05Z","products":[{"vendor":"microsoft","product":"windows 11 version 24h2"},{"vendor":"microsoft","product":"windows 11 version 25h2"},{"vendor":"microsoft","product":"windows 11 version 26h1"},{"vendor":"microsoft","product":"windows server 2025"},{"vendor":"microsoft","product":"windows server 2025 (server core installation)"},{"vendor":"microsoft","product":"windows_11_24h2"},{"vendor":"microsoft","product":"windows_11_25h2"},{"vendor":"microsoft","product":"windows_11_26h1"},{"vendor":"microsoft","product":"windows_server_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83999","tags":["vendor-advisory","patch","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-83999"},{"url":"https://github.com/advisories/GHSA-wwcf-37pw-hpqr"}],"sources":{"cve":[{"id":"CVE-2026-83999","title":"Windows Resilient File System (ReFS) Deduplication Service Elevation of Privilege Vulnerability","description":"Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-09-08T17:14:19.442Z","modified":"2026-11-10T21:33:05.261Z","cvss":[{"version":"3.1","score":7,"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","level":"high","assessor":"cna"}],"cwes":["CWE-59"],"updated_at":"2026-11-10T22:48:54.14451Z"}],"euvd":[{"id":"EUVD-2026-73362","description":"Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-09-08T17:14:19Z","modified":"2026-11-10T21:33:05Z","cvss":[{"version":"3.1","score":7,"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","level":"high"}],"updated_at":"2026-11-10T22:23:49.679186Z"}],"ghsa":[{"id":"GHSA-wwcf-37pw-hpqr","title":"Improper link resolution before file access ('link following') in Windows Resilient File System ...","description":"Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-09-08T18:33:39Z","modified":"2026-09-08T18:34:26Z","cvss":[{"version":"3.1","score":7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-59"],"updated_at":"2026-11-02T15:11:34.690977Z"}],"nvd":[{"id":"CVE-2026-83999","description":"Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-09-08T18:21:10.863Z","modified":"2026-09-11T14:17:36.093Z","cvss":[{"version":"3.1","score":7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-59"],"updated_at":"2026-11-02T14:12:45.264578Z"}]}}