Vulnerability Description
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 10 1607 | < 10.0.14393.9339 |
| Microsoft | Windows 10 1809 | < 10.0.17763.9020 |
| Microsoft | Windows Server 2012 | - |
| Microsoft | Windows Server 2016 | < 10.0.14393.9339 |
| Microsoft | Windows Server 2019 | < 10.0.17763.9020 |
| Microsoft | Windows Server 2022 | < 10.0.20348.5386 |
| Microsoft | Windows Server 2025 | < 10.0.26100.33158 |
Related Weaknesses (CWE)
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-US Government Resource
FAQ
What is CVE-2026-56155?
CVE-2026-56155 is a vulnerability with a CVSS score of 7.8 (HIGH). Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
How severe is CVE-2026-56155?
CVE-2026-56155 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-56155?
Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019.