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CVE-2026-56155

Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability

Microsoft Active Directory Federation ServicesIdentity & access
Open in ThreatlineRecord JSON
CVSS
7.8High
ExploitationExploited in the wildAdded to KEV 14 Jul 2026CISA KEV
Exploit odds (EPSS)0.35%Chance of exploitation activity in the next 30 days, higher than 26% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in10.0.14393.9339Also 10.0.17763.9020, 6.2.9200.26226 and 3 moreCVE List
Federal deadline28 Jul 2026Remediation due date for US federal agenciesCISA KEV
CISA required actionApply 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. CISA KEV

What fixes it

  • 10.0.14393.9339Windows 10 Version 1607CVE List
  • 10.0.17763.9020Windows 10 Version 1809CVE List
  • 6.2.9200.26226Windows Server 2012CVE List
  • 6.2.9200.26226Windows Server 2012 (Server Core installation)CVE List
  • 6.3.9600.23291Windows Server 2012 R2CVE List
  • 6.3.9600.23291Windows Server 2012 R2 (Server Core installation)CVE List
Show all 13 fixed versions
  • 10.0.14393.9339Windows Server 2016CVE List
  • 10.0.14393.9339Windows Server 2016 (Server Core installation)CVE List
  • 10.0.17763.9020Windows Server 2019CVE List
  • 10.0.17763.9020Windows Server 2019 (Server Core installation)CVE List
  • 10.0.20348.5386Windows Server 2022CVE List
  • 10.0.26100.33158Windows Server 2025CVE List
  • 10.0.26100.33158Windows Server 2025 (Server Core installation)CVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 14 Jul 2026Added to CISA KEVCISA KEV
  2. 14 Jul 2026, 17:05 UTCPublishedCVE List

Description

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

Text from CVE List

Affected versions 13

  • Windows 10 Version 1607affected: 10.0.14393.0 before 10.0.14393.9339CVE List
  • Windows 10 Version 1809affected: 10.0.17763.0 before 10.0.17763.9020CVE List
  • Windows Server 2012affected: 6.2.9200.0 before 6.2.9200.26226CVE List
  • Windows Server 2012 (Server Core installation)affected: 6.2.9200.0 before 6.2.9200.26226CVE List
  • Windows Server 2012 R2affected: 6.3.9600.0 before 6.3.9600.23291CVE List
  • Windows Server 2012 R2 (Server Core installation)affected: 6.3.9600.0 before 6.3.9600.23291CVE List
  • Windows Server 2016affected: 10.0.14393.0 before 10.0.14393.9339CVE List
  • Windows Server 2016 (Server Core installation)affected: 10.0.14393.0 before 10.0.14393.9339CVE List
  • Windows Server 2019affected: 10.0.17763.0 before 10.0.17763.9020CVE List
  • Windows Server 2019 (Server Core installation)affected: 10.0.17763.0 before 10.0.17763.9020CVE List
  • Windows Server 2022affected: 10.0.20348.0 before 10.0.20348.5386CVE List
  • Windows Server 2025affected: 10.0.26100.0 before 10.0.26100.33158CVE List
  • Windows Server 2025 (Server Core installation)affected: 10.0.26100.0 before 10.0.26100.33158CVE List

References 5