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MC1442510 — 90-Day Reminder: AD FS DKM container ACL hardening begins in October 2026

MC1442510WindowsstayInformedUpdated: 29 July 2026

What and whyWindows updates released in October 2026 will begin Enforcement mode for AD FS Distributed Key Manager (DKM) container ACL hardening. This change is designed to address the elevation of privilege vulnerability documented in CVE-2026-56155 by automatically remediating insecure DKM container ACL configurations on supported Windows Server versions. Organizations using Active Directory Federation Services (AD FS) should use the current Audit mode period to review DKM container permission...

Applies to: Windows
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).