CVE-2026-56155
Active Directory Federation Services Elevation of Privilege Vulnerability
- Published
- Updated
- Reserved
- Assigned by
- microsoft
Description
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability.
- Added
- 14 Jul 2026
- Fix due (US federal)
- 28 Jul 2026
- Used by ransomware
- Not known
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| microsoftCNA (assigner) | 3.1 | High7.8 | 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 |
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.35% · top 72% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
Microsoft · Windows 10 Version 1607
- affected 10.0.14393.0 – < 10.0.14393.9339
Microsoft · Windows 10 Version 1809
- affected 10.0.17763.0 – < 10.0.17763.9020
Microsoft · Windows Server 2012
- affected 6.2.9200.0 – < 6.2.9200.26226
Microsoft · Windows Server 2012 (Server Core installation)
- affected 6.2.9200.0 – < 6.2.9200.26226
Microsoft · Windows Server 2012 R2
- affected 6.3.9600.0 – < 6.3.9600.23291
Microsoft · Windows Server 2012 R2 (Server Core installation)
- affected 6.3.9600.0 – < 6.3.9600.23291
Microsoft · Windows Server 2016
- affected 10.0.14393.0 – < 10.0.14393.9339
Microsoft · Windows Server 2016 (Server Core installation)
- affected 10.0.14393.0 – < 10.0.14393.9339
Microsoft · Windows Server 2019
- affected 10.0.17763.0 – < 10.0.17763.9020
Microsoft · Windows Server 2019 (Server Core installation)
- affected 10.0.17763.0 – < 10.0.17763.9020
Microsoft · Windows Server 2022
- affected 10.0.20348.0 – < 10.0.20348.5386
Microsoft · Windows Server 2025
- affected 10.0.26100.0 – < 10.0.26100.33158
Microsoft · Windows Server 2025 (Server Core installation)
- affected 10.0.26100.0 – < 10.0.26100.33158
References (2)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-56155)Record last updated .