{"id":"CVE-2026-83511","aliases":["EUVD-2026-99907","GHSA-v723-46xp-3rqv"],"status":"published","title":"Active Directory Federation Services (AD FS) Spoofing Vulnerability","description":"Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00652,"percentile":0.51751,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1390"],"published":"2026-10-13T19:00:46Z","modified":"2026-11-10T20:41:46Z","products":[{"vendor":"microsoft","product":"windows 10 version 1607"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows server 2012 r2"},{"vendor":"microsoft","product":"windows server 2012 r2 (server core installation)"},{"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 2022"},{"vendor":"microsoft","product":"windows server 2025"},{"vendor":"microsoft","product":"windows server 2025 (server core installation)"},{"vendor":"microsoft","product":"windows_10_1607"},{"vendor":"microsoft","product":"windows_10_1809"},{"vendor":"microsoft","product":"windows_server_2012"},{"vendor":"microsoft","product":"windows_server_2016"},{"vendor":"microsoft","product":"windows_server_2019"},{"vendor":"microsoft","product":"windows_server_2022"},{"vendor":"microsoft","product":"windows_server_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83511","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-83511"},{"url":"https://github.com/advisories/GHSA-v723-46xp-3rqv"}],"sources":{"cve":[{"id":"CVE-2026-83511","title":"Active Directory Federation Services (AD FS) Spoofing Vulnerability","description":"Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T19:00:46.958Z","modified":"2026-11-10T20:41:46.626Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"cwes":["CWE-1390"],"updated_at":"2026-11-10T22:18:28.707469Z"}],"euvd":[{"id":"EUVD-2026-99907","description":"Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T19:00:46Z","modified":"2026-11-10T20:41:46Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-10T22:23:58.135191Z"}],"ghsa":[{"id":"GHSA-v723-46xp-3rqv","title":"Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized...","description":"Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T21:34:26Z","modified":"2026-10-13T21:34:33Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-1390"],"updated_at":"2026-11-02T15:13:16.244853Z"}],"nvd":[{"id":"CVE-2026-83511","description":"Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T19:19:56.46Z","modified":"2026-10-28T18:15:22.017Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-1390"],"updated_at":"2026-11-02T14:12:57.603498Z"}]}}