High · 7.8 Known exploited CVE-2026-56155 EUVD-2026-44042GHSA-p436-qch3-9m59

Active Directory Federation Services Elevation of Privilege Vulnerability

Published Jul 14, 2026 · Updated Nov 10, 2026 · Assigned by microsoft

Vendor: Microsoft Product: Windows 10 Version 1607 Product: Windows 10 Version 1809 Product: Windows Server 2012 Product: Windows Server 2012 (Server Core installation) Product: Windows Server 2012 R2 Product: Windows Server 2012 R2 (Server Core installation) Product: Windows Server 2016 Product: Windows Server 2016 (Server Core installation) Product: Windows Server 2019 Product: Windows Server 2019 (Server Core installation) Product: Windows Server 2022 Product: Windows Server 2025 Product: Windows Server 2025 (Server Core installation) Platform: Windows

Description

Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.

Affected products

Vendor	Product	Affected	Fixed
Microsoft	Windows 10 Version 1607	10.0.14393.0 – < 10.0.14393.9339	10.0.14393.9339
Microsoft	Windows 10 Version 1809	10.0.17763.0 – < 10.0.17763.9020	10.0.17763.9020
Microsoft	Windows Server 2012	6.2.9200.0 – < 6.2.9200.26226	6.2.9200.26226
Microsoft	Windows Server 2012 (Server Core installation)	6.2.9200.0 – < 6.2.9200.26226	6.2.9200.26226
Microsoft	Windows Server 2012 R2	6.3.9600.0 – < 6.3.9600.23291	6.3.9600.23291
Microsoft	Windows Server 2012 R2 (Server Core installation)	6.3.9600.0 – < 6.3.9600.23291	6.3.9600.23291
Microsoft	Windows Server 2016	10.0.14393.0 – < 10.0.14393.9339	10.0.14393.9339
Microsoft	Windows Server 2016 (Server Core installation)	10.0.14393.0 – < 10.0.14393.9339	10.0.14393.9339
Microsoft	Windows Server 2019	10.0.17763.0 – < 10.0.17763.9020	10.0.17763.9020
Microsoft	Windows Server 2019 (Server Core installation)	10.0.17763.0 – < 10.0.17763.9020	10.0.17763.9020
Microsoft	Windows Server 2022	10.0.20348.0 – < 10.0.20348.5386	10.0.20348.5386
Microsoft	Windows Server 2025	10.0.26100.0 – < 10.0.26100.33158	10.0.26100.33158
Microsoft	Windows Server 2025 (Server Core installation)	10.0.26100.0 – < 10.0.26100.33158	10.0.26100.33158

Advisories 3

WID-SEC-2026-2316 Microsoft Windows Produkte: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 6, 2026
NCSC-2026-0231 Kwetsbaarheden verholpen in Microsoft Windows NCSC-NL (Netherlands) · Jul 14, 2026
MSRC-CVE-2026-56155 Active Directory Federation Services Elevation of Privilege Vulnerability Microsoft Security Response Center · Jul 14, 2026

References

Active Directory Federation Services Elevation of Privilege Vulnerability vendor-advisory patch