Ubuntu 26.10 Drops Btrfs, XFS and ZFS /Boot with Secure Boot
a day ago
- Canonical has changed how Ubuntu 26.10 boots with Secure Boot enabled by removing support for certain filesystems in the signed GRUB, including Btrfs, XFS, ZFS, LVM, LUKS, and software RAID (except RAID1), as well as HFS+, Apple partition support, and JPEG/PNG loading.
- For Secure Boot systems, /boot remains supported only on ext4, FAT, ISO9660, and squashfs for snaps; if Secure Boot is disabled, the full GRUB feature set is available.
- The change aims to reduce the attack surface by eliminating GRUB parsers that have been sources of Secure Boot bypass vulnerabilities, especially as LLMs make vulnerabilities easier to find.
- This change follows an LTS release; users who need both Secure Boot and full GRUB functionality can stick with Ubuntu 26.04 LTS, which is supported until 2036 or 2041 with Ubuntu Pro.
- Most users will not be affected because the standard Ubuntu installer uses a default /boot layout on supported filesystems.