Actively exploited in the wild
Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability
Microsoft - Active Directory Federation Services · Listed in the CISA KEV since 2026-07-14. This indicates confirmed attacks in production environments.
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.
CVE-2026-56155
HighCVSS 7.8KEVExploitation Probability (EPSS)
Low risk30th percentile - higher than 30% of all known CVEs
Summary
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
Risk Assessment
The risk is that an authorized user can gain higher privileges within the system, potentially leading to unauthorized access to sensitive data or compromise of the federation service.
Recommendation
Apply security patches provided by the vendor for Active Directory Federation Services immediately. Also review and harden the access control configuration in AD FS.
Original NVD description (English source)
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.