Microsoft Fixes Windows 11 KB5089549 Install Failures Caused by Limited EFI Partition Space

Microsoft has fixed the known issue that caused installation failures and 0x800f0922 errors when deploying the May 26, 2026, Windows 11 security update KB5089549 . The solution is included in the KB5089573 preview cumulative update released on May 26 and will be available to all users through the June Patch Tuesday updates later this month. The failures were due to insufficient free space on the EFI System Partition (ESP), which led the update to roll back automatically on affected devices.