{"id":"CVE-2026-56155","aliases":["EUVD-2026-44042","GHSA-p436-qch3-9m59"],"status":"published","title":"Active Directory Federation Services Elevation of Privilege Vulnerability","description":"Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.","severity":{"version":"3.1","score":7.8,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00346,"percentile":0.28565,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":false,"fix_available":false},"cwes":["CWE-1220"],"published":"2026-07-14T17:05:11Z","modified":"2026-11-01T17:32:48Z","kev":{"date_added":"2026-07-14","due_date":"2026-07-28","required_action":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","known_ransomware_use":"Unknown"},"exploitation":[{"source":"euvd","since":"2026-07-14"},{"source":"kev","since":"2026-07-14"}],"products":[{"vendor":"microsoft","product":"active directory federation services"},{"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-2026-56155","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56155","tags":["government-resource","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56155"},{"url":"https://github.com/advisories/GHSA-p436-qch3-9m59"}],"sources":{"cve":[{"id":"CVE-2026-56155","title":"Active Directory Federation Services Elevation of Privilege Vulnerability","description":"Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-07-14T17:05:11.702Z","modified":"2026-11-10T22:35:43.186Z","cvss":[{"version":"3.1","score":7.8,"vector":"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","level":"high","assessor":"cna"}],"cwes":["CWE-1220"],"updated_at":"2026-11-10T23:49:29.755102Z"}],"euvd":[{"id":"EUVD-2026-44042","description":"Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-07-14T17:05:11Z","modified":"2026-11-10T22:35:43Z","cvss":[{"version":"3.1","score":7.8,"vector":"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","level":"high"}],"exploited_since":"2026-07-14","updated_at":"2026-11-10T23:24:15.503335Z"}],"ghsa":[{"id":"GHSA-p436-qch3-9m59","title":"Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows...","description":"Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-07-14T18:32:10Z","modified":"2026-07-14T21:32:52Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-1220"],"updated_at":"2026-11-02T15:09:31.957545Z"}],"kev":[{"id":"CVE-2026-56155","title":"Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability ","description":"Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.","cwes":["CWE-1220"],"kev":{"date_added":"2026-07-14","due_date":"2026-07-28","required_action":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","known_ransomware_use":"Unknown"},"updated_at":"2026-11-02T17:00:15.999436Z"}],"nvd":[{"id":"CVE-2026-56155","description":"Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.","status":"published","published":"2026-07-14T17:17:09.763Z","modified":"2026-07-15T14:18:24.01Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-1220"],"updated_at":"2026-11-02T14:12:29.489525Z"}]}}