Debian Server 11 Bullseye Update

Debian 11 (bullseye) release notes for ARM EABI describe the upgrade from buster, major package and desktop updates, and important operational changes such as cgroup v2, persistent journaling, and exFAT support. They also document upgrade cautions, deprecations, and known severe bugs.

• Password hashing defaults to yescrypt for local accounts, improving resistance to dictionary attacks.
• Linux 5.10 enables user namespaces by default to improve sandboxing for browsers and container tools.
• Linux disables unprivileged bpf() calls by default for security hardening.
• Security support is limited for some browser engines and Go-based packages; they may not receive full backported security fixes.

• OpenSSH upgrade may temporarily block new SSH connections during the upgrade window.
• Open vSwitch may require an /etc/network/interfaces change to recover bridges after boot.
• rsync --noatime was renamed to --open-noatime; older scripts may need updating.
• libgc1c2-dependent packages may require running the upgrade twice.
• fuse3 replaces fuse for packages such as gvfs-fuse, kio-fuse, and sshfs.

• Driverless printing now includes USB printers via ipp-usb.
• Driverless scanning is supported through sane-escl and sane-airscan.
• A new generic open command is available as an alias for xdg-open or run-mailcap.
• Systemd defaults to cgroup v2.
• Persistent systemd journal storage is enabled by default.
• Kernel support for exFAT is included and used by default.
• Fcitx 5 is introduced as the new input method framework.
• Bazel is available in Debian as bazel-bootstrap.

• The rescue boot option is unusable without a root password unless SYSTEMD_SULOGIN_FORCE=1 is configured.
• 32-bit Xen PV guests are no longer supported.
• XFS no longer supports the barrier and nobarrier mount options.
• Some Intel microcode updates may break Wi-Fi or cause boot hangs on affected systems.
• Exim 4.94 introduces tainted-data handling that can break older configurations.
• The release notes list multiple known severe bugs affecting packages such as cron, fail2ban, openssh-server, mariadb-server-10.5, and others.

• Upgrade from Debian 10 (buster) only; direct upgrades from older releases are not supported.
• Use apt upgrade --without-new-pkgs for a minimal upgrade before apt full-upgrade when needed.
• Record the upgrade session with script to aid troubleshooting.
• Update APT sources from buster/updates to bullseye-security.
• Install a linux-image-* metapackage before rebooting after the upgrade.
• Back up /etc, /var/lib/dpkg, and /var/lib/apt/extended_states before upgrading.
• For OpenStack nodes, cgroup v1 may need to be restored with kernel command-line parameters.
• If using NIS/NIS+, install libnss-nis and libnss-nisplus after upgrading.

• Debian 11 bullseye release notes
  https://www.debian.org/releases/bullseye/releasenotes
• Debian 11 installer and installation guide
  https://www.debian.org/releases/bullseye/debian-installer/

Product Information

Vendor: Debian

Product: Server

Product type: Software

Application category: Utilities

Platform: Linux

Variant: 11 Bullseye

Vendor release date: Aug 31, 2024

Original release notes: View on vendor site

Published on updatealert.io: Jul 31, 2026