CVE-2026-56155
Microsoft Active Directory Federation Services
Summary
Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
Published 2026-07-14 · first seen here 2026-10-10
CISA required action (due 2026-07-28): 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.
Analysis & write-ups
No technical write-up from a research team yet. Contact Zero checks Unit 42, Google/Mandiant, Microsoft, Talos, CrowdStrike, Rapid7, watchTowr and others several times a day, plus NVD and CISA reference links.
Hunt & detect
Threat hunt brief, Sigma rule and Splunk / Sentinel / CrowdStrike queries are not available for this item yet.
References
- NVD entry
- CISA KEV
- https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-56155
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://learn.microsoft.com/en-us/windows-server/identity/ad-fs/decommission/adfs-decommission-guide