{"id":"CVE-2026-83645","aliases":["EUVD-2026-99934","GHSA-jf3j-vmpw-44fm"],"status":"published","title":"Active Directory Federation Services (AD FS) Denial of Service Vulnerability","description":"Allocation of resources without limits or throttling in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01222,"percentile":0.69101,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-770"],"published":"2026-10-13T19:00:49Z","modified":"2026-11-10T20:42:03Z","products":[{"vendor":"microsoft","product":"windows 10 version 1607"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows server 2012"},{"vendor":"microsoft","product":"windows server 2012 (server core installation)"},{"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-2026-83645","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-83645"},{"url":"https://github.com/advisories/GHSA-jf3j-vmpw-44fm"}],"sources":{"cve":[{"id":"CVE-2026-83645","title":"Active Directory Federation Services (AD FS) Denial of Service Vulnerability","description":"Allocation of resources without limits or throttling in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T19:00:49.624Z","modified":"2026-11-10T20:42:03.351Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-10T22:18:28.707469Z"}],"euvd":[{"id":"EUVD-2026-99934","description":"Allocation of resources without limits or throttling in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T19:00:49Z","modified":"2026-11-10T20:42:03Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-10T22:23:57.623557Z"}],"ghsa":[{"id":"GHSA-jf3j-vmpw-44fm","title":"Allocation of resources without limits or throttling in Active Directory Federation Services (AD...","description":"Allocation of resources without limits or throttling in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T21:34:31Z","modified":"2026-10-13T21:34:31Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:13:16.244853Z"}],"nvd":[{"id":"CVE-2026-83645","description":"Allocation of resources without limits or throttling in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T19:20:05.5Z","modified":"2026-10-29T18:18:28.73Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:57.603498Z"}]}}