{"id":"CVE-2021-26866","aliases":["EUVD-2021-13650","GHSA-8pv9-vfqj-q49w"],"status":"published","title":"Windows Update Service Elevation of Privilege Vulnerability","description":"Windows Update Service Elevation of Privilege Vulnerability","severity":{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.01157,"percentile":0.67508,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-269","CWE-59"],"published":"2021-03-11T15:38:37Z","modified":"2026-08-19T18:32:32Z","products":[{"vendor":"microsoft","product":"windows 10 version 1507"},{"vendor":"microsoft","product":"windows 10 version 1607"},{"vendor":"microsoft","product":"windows 10 version 1803"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows 10 version 1909"},{"vendor":"microsoft","product":"windows 10 version 2004"},{"vendor":"microsoft","product":"windows 10 version 20h2"},{"vendor":"microsoft","product":"windows server 2016"},{"vendor":"microsoft","product":"windows server 2016 (server core installation)"},{"vendor":"microsoft","product":"windows server 2019"},{"vendor":"microsoft","product":"windows server 2019 (server core installation)"},{"vendor":"microsoft","product":"windows server version 2004"},{"vendor":"microsoft","product":"windows server version 20h2"},{"vendor":"microsoft","product":"windows server, version 1909 (server core installation)"},{"vendor":"microsoft","product":"windows_10"},{"vendor":"microsoft","product":"windows_server_2016"},{"vendor":"microsoft","product":"windows_server_2019"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26866","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26866","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-286/","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26866"},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-286"},{"url":"https://github.com/advisories/GHSA-8pv9-vfqj-q49w"}],"sources":{"cve":[{"id":"CVE-2021-26866","title":"Windows Update Service Elevation of Privilege Vulnerability","description":"Windows Update Service Elevation of Privilege Vulnerability","status":"published","published":"2021-03-11T15:38:37Z","modified":"2026-08-19T16:30:20.83Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"updated_at":"2026-11-02T14:32:57.368269Z"}],"euvd":[{"id":"EUVD-2021-13650","description":"Windows Update Service Elevation of Privilege Vulnerability","status":"published","published":"2021-03-11T15:38:37Z","modified":"2026-08-19T16:30:20Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-02T18:01:42.811156Z"}],"ghsa":[{"id":"GHSA-8pv9-vfqj-q49w","title":"Windows Update Service Elevation of Privilege Vulnerability","description":"Windows Update Service Elevation of Privilege Vulnerability","status":"published","published":"2022-05-24T17:44:19Z","modified":"2026-08-19T18:32:32Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"medium"}],"cwes":["CWE-59","CWE-269"],"updated_at":"2026-11-02T15:10:42.300371Z"}],"nvd":[{"id":"CVE-2021-26866","description":"Windows Update Service Elevation of Privilege Vulnerability","status":"published","published":"2021-03-11T16:15:14.44Z","modified":"2026-08-19T17:17:40.377Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"medium","assessor":"secondary"},{"version":"2.0","score":3.6,"vector":"AV:L/AC:L/Au:N/C:N/I:P/A:P","level":"low","assessor":"primary"}],"cwes":["CWE-59"],"updated_at":"2026-11-02T14:06:50.805771Z"}]}}