{"id":"CVE-2026-85321","state":"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.","publishedAt":"2026-10-13T19:00:01.422Z","updatedAt":"2026-10-30T19:05:32.754Z","severity":{"score":7.5,"label":"High","version":"3.1","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","source":"microsoft"},"assigner":"microsoft","products":["Microsoft Windows Server 2012 R2","Microsoft Windows Server 2012 R2 (Server Core installation)","Microsoft Windows Server 2016","Microsoft Windows Server 2016 (Server Core installation)","Microsoft Windows Server 2019","Microsoft Windows Server 2019 (Server Core installation)","Microsoft Windows Server 2022","Microsoft Windows Server 2025","Microsoft Windows Server 2025 (Server Core installation)"],"affected":[{"vendor":"Microsoft","product":"Windows Server 2012 R2","versions":[{"version":"6.3.9600.0","status":"affected","lessThan":"6.3.9600.23470","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2012 R2 (Server Core installation)","versions":[{"version":"6.3.9600.0","status":"affected","lessThan":"6.3.9600.23470","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2016","versions":[{"version":"10.0.14393.0","status":"affected","lessThan":"10.0.14393.9612","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2016 (Server Core installation)","versions":[{"version":"10.0.14393.0","status":"affected","lessThan":"10.0.14393.9612","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2019","versions":[{"version":"10.0.17763.0","status":"affected","lessThan":"10.0.17763.9376","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2019 (Server Core installation)","versions":[{"version":"10.0.17763.0","status":"affected","lessThan":"10.0.17763.9376","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2022","versions":[{"version":"10.0.20348.0","status":"affected","lessThan":"10.0.20348.5761","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2025","versions":[{"version":"10.0.26100.0","status":"affected","lessThan":"10.0.26100.33650","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2025 (Server Core installation)","versions":[{"version":"10.0.26100.0","status":"affected","lessThan":"10.0.26100.33650","versionType":"custom"}],"platforms":["x64-based Systems"]}],"references":["https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85321"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-30T19:30:04.431Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/85xxx/CVE-2026-85321.json","commit":"a3048093a4809ba3e15db7a610bbd66f60b789d3","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-85321","state":"PUBLISHED","datePublished":"2026-10-13T19:00:01.422Z","dateUpdated":"2026-10-30T19:05:32.754Z","assignerShortName":"microsoft","assignerOrgId":"f38d906d-7342-40ea-92c1-6c4a2c6478c8","dateReserved":"2026-09-03T17:01:56.594Z"},"containers":{"cna":{"title":"Active Directory Federation Services (AD FS) Denial of Service Vulnerability","descriptions":[{"lang":"en-US","value":"Allocation of resources without limits or throttling in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network."}],"affected":[{"vendor":"Microsoft","product":"Windows Server 2012 R2","versions":[{"version":"6.3.9600.0","status":"affected","lessThan":"6.3.9600.23470","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2012 R2 (Server Core installation)","versions":[{"version":"6.3.9600.0","status":"affected","lessThan":"6.3.9600.23470","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2016","versions":[{"version":"10.0.14393.0","status":"affected","lessThan":"10.0.14393.9612","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2016 (Server Core installation)","versions":[{"version":"10.0.14393.0","status":"affected","lessThan":"10.0.14393.9612","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2019","versions":[{"version":"10.0.17763.0","status":"affected","lessThan":"10.0.17763.9376","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2019 (Server Core installation)","versions":[{"version":"10.0.17763.0","status":"affected","lessThan":"10.0.17763.9376","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2022","versions":[{"version":"10.0.20348.0","status":"affected","lessThan":"10.0.20348.5761","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2025","versions":[{"version":"10.0.26100.0","status":"affected","lessThan":"10.0.26100.33650","versionType":"custom"}],"platforms":["x64-based Systems"]},{"vendor":"Microsoft","product":"Windows Server 2025 (Server Core installation)","versions":[{"version":"10.0.26100.0","status":"affected","lessThan":"10.0.26100.33650","versionType":"custom"}],"platforms":["x64-based Systems"]}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85321","name":"Active Directory Federation Services (AD FS) Denial of Service Vulnerability","tags":["vendor-advisory","patch"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en-US","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","baseSeverity":"HIGH","baseScore":7.5,"vectorString":"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","description":"CWE-770: Allocation of Resources Without Limits or Throttling","lang":"en-US","type":"CWE"}]}],"providerMetadata":{"shortName":"microsoft","orgId":"f38d906d-7342-40ea-92c1-6c4a2c6478c8","dateUpdated":"2026-10-30T19:05:32.754Z"},"datePublic":"2026-10-13T14:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*","versionStartIncluding":"10.0.17763.0","versionEndExcluding":"10.0.17763.9376"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*","versionStartIncluding":"10.0.17763.0","versionEndExcluding":"10.0.17763.9376"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*","versionStartIncluding":"10.0.20348.0","versionEndExcluding":"10.0.20348.5761"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*","versionStartIncluding":"10.0.26100.0","versionEndExcluding":"10.0.26100.33650"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*","versionStartIncluding":"10.0.26100.0","versionEndExcluding":"10.0.26100.33650"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*","versionStartIncluding":"10.0.14393.0","versionEndExcluding":"10.0.14393.9612"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*","versionStartIncluding":"10.0.14393.0","versionEndExcluding":"10.0.14393.9612"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*","versionStartIncluding":"6.3.9600.0","versionEndExcluding":"6.3.9600.23470"},{"vulnerable":true,"criteria":"cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*","versionStartIncluding":"6.3.9600.0","versionEndExcluding":"6.3.9600.23470"}]}]}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-85321","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-13T20:15:28.381650Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-13T20:23:27.996Z"}}]}}}