Microsoft expands Secure Boot fixes as Windows updates hit install and recovery issues

Microsoft released the June cumulative update KB5093998 for Windows 11 23H2 with security fixes, broader Secure Boot certificate rollout support, and a new Group Policy/MDM option to limit Secure Boot service data sent to Microsoft. The update also fixes a known issue that could force some devices into BitLocker Recovery after boot file updates, while CERT/CC and Microsoft separately published advisories on a Secure Boot bypass affecting Microsoft-signed UEFI shim bootloaders, tracked as CVE-2026-44815.

At the same time, Microsoft warned that some PCs upgraded from Windows 10 21H2/22H2 or Windows 11 23H2 to Windows 11 24H2 or 25H2 may fail to install the June 2026 cumulative updates, showing errors 0x80073712 or 0x800f0993 because of package and component store issues. Microsoft said an automatic fix is rolling out for unmanaged enterprise and Home devices after restart, while already affected systems may require removing a problematic package with DISM or performing an in-place upgrade; separate reporting also said recent HP BIOS updates and Dell SupportAssist software caused BitLocker loops and BSODs that were initially blamed on Windows but traced to OEM firmware and utilities.