CVE-2026-56155

Insufficient Granularity of Access Control in Microsoft Active Directory Federation Services. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 14 July 2026.

Product
Microsoft Active Directory Federation Services
Added to CISA's catalog
Federal fix-by date
Ransomware
No known use in ransomware campaigns

CISA’s description.

Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.

Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.