Boot Partition Bottleneck: Microsoft Confirms Windows 11 Update KB5089549 Fails with Error 0x800f0922

Windows 11 update KB5089549 is causing installation failures on devices with ≤10MB free in the EFI System Partition (ESP); the update progresses to ~35% then aborts during reboot, producing rollback and error codes (e.g., 0x800f0922, ServicingBootFiles 0x70). Microsoft deployed a cloud-delivered Known Issue Rollback for consumer devices and provided a Group Policy MSI for enterprises to mitigate the issue pending a permanent fix.