ubuntu / grub / bootloader

Ubuntu developers propose stripping several GRUB features from signed builds in 26.10 to reduce attack surface for Secure Boot. The changes would remove support for btrfs, hfsplus, xfs, zfs filesystems, JPEG/PNG image formats, part_apple partition parsing, most RAID types (keeping RAID1), while retaining ext4, FAT, ISO9660, GPT/MBR partition support, LVM, md-raid (except RAID0/RAID5/etc.), and LUKS. The result forces /boot onto a raw ext4 partition, preventing encrypted or ZFS/XFS/Btrfs /boot setups under Secure Boot. Ubuntu plans to keep full-featured GRUB without Secure Boot, and block upgrades from affected systems staying on 26.04 LTS by default. The proposal aims to harden supply-chain/boot security but has ignited concerns about compatibility for Btrfs, software RAID, non-UEFI environments, and multi-arch/legacy deployments.

Ubuntu plans to remove or limit certain GRUB features in the upcoming 26.10 release to harden boot security, prompting debate about compatibility with setups like LUKS-encrypted /boot and signed grub.cfg. The discussion on Hacker News highlights concerns that full-disk encryption requirements in some regions could conflict with changes that expose plaintext boot data, and users question whether GRUB needs to be replaced or simplified. Commenters suggested alternatives such as systemd-boot or a Rust-based bootloader, while others warned against expanding systemd’s footprint. The move matters because GRUB changes affect distro compatibility, enterprise security compliance, and the future of Linux boot architectures.

Ubuntu developers propose stripping many GRUB features from signed builds in the 26.10 release to reduce attack surface for Secure Boot. The plan would retain ext4, FAT, iso9660 and squashfs but remove filesystem drivers (btrfs, hfsplus, xfs, zfs), image formats (jpeg, png), part_apple partition support, some RAID types (keeping raid1), while continuing LVM, md-raid (except some types) and LUKS. Affected systems would require /boot on raw ext4 and encrypted /boot would no longer be allowed under Secure Boot; upgrades from 26.04 LTS would be blocked by default. The change is intended to improve security and simplify future boot strategies, but has drawn pushback from users relying on btrfs, non-ext4 setups, RAID configurations, and multi-arch or non-UEFI environments.

Ubuntu Looks To Strip GRUB To The Bare Minimum For Better Security