kb5081151

KB5081151 is a Safe OS Dynamic Update for Windows 11 version 26H1, released by Microsoft on March 26, 2026. This update addresses the upcoming June 2026 Secure Boot certificate expiration by ensuring the pre-boot trust chain remains intact. It is part of Microsoft's broader effort to transition from older 2011-era certificates to newer 2023 certificates across consumer PCs, commercial fleets, virtualized environments, and managed devices. According to Microsoft's support guidance, devices lacking the newer certificates will continue to boot and receive normal Windows updates, but the update helps prepare systems for the eventual certificate change. This tag covers discussions about the KB5081151 update, its role in Secure Boot certificate management, and its implications for Windows 11 users.