{"id":"CVE-2026-56155","title":"Active Directory Federation Services Elevation of Privilege Vulnerability","summary":"Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C","cvssSource":"cna","cwe":["CWE-1220"],"vendor":"Microsoft","product":"Windows 10 Version 1607","affected":["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_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":"active","automatable":"no","technicalImpact":"total","timestamp":"2026-07-15T03:55:53.880960Z"},"exploited":true,"exploitAvailable":true,"published":"2026-07-14","updated":"2026-09-17","sourceUpdated":"2026-09-17T22:29:12.036Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-56155","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155","label":"Active Directory Federation Services Elevation of Privilege Vulnerability"}],"tags":["cve.org","in-the-wild","exploit-available","kev"],"epss":0.00346,"epssPercentile":0.2816,"kev":true,"kevDateAdded":"2026-07-14","kevDueDate":"2026-07-28","kevRansomware":false,"zeroDay":true,"ingestedAt":"2026-09-08T17:06:31.928Z","slug":"CVE-2026-56155","body":"## Overview\n\nInsufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.\n\n## Affected\n\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_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":"abyssal","depthScore":68,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":25,"ransomware":0},"changes":[]}