{"id":"CVE-2026-50647","title":"Active Directory Federation Server Denial of Service Vulnerability","summary":"Loop with unreachable exit condition ('infinite loop') in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.","severity":"high","cvss":7.5,"cvssVector":"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","cvssSource":"cna","cwe":["CWE-835"],"vendor":"Microsoft","product":"Microsoft .NET Framework 3.5 AND 4.7.2","affected":[".net_framework_3.5_and_4.7.2 >= 4.7.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0",".net_framework_3.5_and_4.8 >= 4.8.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0",".net_framework_3.5_and_4.8.1 >= 4.8.1 < 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0",".net_framework_4.6.2_4.7_4.7.1_4.7.2 >= 4.7.0 < 4.7.4143.0",".net_framework_4.8 >= 4.8.0 < 4.8.4803.0",".net_framework_4.8.1 >= 4.8.0.0 < 4.8.9340.0","windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9339","windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.9020","windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7548","windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7548","windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875","windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875","windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525","windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26226","windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26226","windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23291","windows_server_2012_r2_server_core_installation >= 6.3.9600.0 < 6.3.9600.23291","windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9339","windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9339","windows_server_2019 >= 10.0.17763.0 < 10.0.17763.9020","windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.9020","windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5386","windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158","windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33158"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-07-14T20:35:05.015074Z"},"published":"2026-07-14","updated":"2026-09-17","sourceUpdated":"2026-09-17T22:32:03.581Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-50647","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50647","label":"Active Directory Federation Server Denial of Service Vulnerability"}],"tags":["cve.org"],"epss":0.01174,"epssPercentile":0.66155,"ingestedAt":"2026-09-08T17:06:31.913Z","slug":"CVE-2026-50647","body":"## Overview\n\nLoop with unreachable exit condition ('infinite loop') in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.\n\n## Affected\n\n- `.net_framework_3.5_and_4.7.2 >= 4.7.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0`\n- `.net_framework_3.5_and_4.8 >= 4.8.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0`\n- `.net_framework_3.5_and_4.8.1 >= 4.8.1 < 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0`\n- `.net_framework_4.6.2_4.7_4.7.1_4.7.2 >= 4.7.0 < 4.7.4143.0`\n- `.net_framework_4.8 >= 4.8.0 < 4.8.4803.0`\n- `.net_framework_4.8.1 >= 4.8.0.0 < 4.8.9340.0`\n- `windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9339`\n- `windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.9020`\n- `windows_10_version_21h2 >= 10.0.19044.0 < 10.0.19044.7548`\n- `windows_10_version_22h2 >= 10.0.19045.0 < 10.0.19045.7548`\n- `windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875`\n- `windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875`\n- `windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525`\n- `windows_server_2012 >= 6.2.9200.0 < 6.2.9200.26226`\n- `windows_server_2012_server_core_installation >= 6.2.9200.0 < 6.2.9200.26226`\n- `windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23291`\n- `windows_server_2012_r2_server_core_installation >= 6.3.9600.0 < 6.3.9600.23291`\n- `windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9339`\n- `windows_server_2016_server_core_installation >= 10.0.14393.0 < 10.0.14393.9339`\n- `windows_server_2019 >= 10.0.17763.0 < 10.0.17763.9020`\n- `windows_server_2019_server_core_installation >= 10.0.17763.0 < 10.0.17763.9020`\n- `windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5386`\n- `windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158`\n- `windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33158`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}