Ubuntu 26.10 Looks To Strip Its GRUB Bootloader To The Bare Minimum For Better Security

Canonical is planning to strip the signed GRUB bootloader in Ubuntu 26.10 down to bare essentials to improve security. The change would remove support for Btrfs, XFS, ZFS, LVM, most RAID configurations, and LUKS-encrypted disks from the signed GRUB builds used for Secure Boot. As a result, most Ubuntu 26.10 installations would require a plain EXT4 /boot partition. These features remain available via unsigned GRUB builds, but at the cost of losing UEFI Secure Boot compliance. The Ubuntu 26.04 LTS upgrader will block upgrades for systems using affected boot configurations to prevent breakage.