Ubuntu Core 26 ReleaseUbuntu Core 26 Release (Image © Canonical)

Transition to a Rust-Based Foundation

A key focus of Ubuntu 26.10 is improving system security and maintainability by using the Rust programming language for core system utilities.

Complete Migration of Coreutils to Rust

The operating system has fully migrated its default core utilities to the Rust-based implementation known as uutils. This migration is now complete, following the replacement of the last remaining GNU utilities—specifically cp, mv, and rm. This transition aims to leverage Rust’s memory safety guarantees at the most fundamental level of the operating system.

Implementation of Sequoia PGP

Ubuntu 26.10 integrates Sequoia PGP into the main repository. Sequoia is a modern, memory-safe implementation of the OpenPGP standard. While the traditional gpg and gpgv utilities remain available in the repository for compatibility reasons, Sequoia is set to become the default toolchain, with sq and sqv serving as the primary utilities for encryption and verification.

Technical Updates for Ubuntu Server

The server edition of Ubuntu 26.10 introduces several package updates and configuration changes to improve security and protocol support.

Split of the OpenSSH Security Architecture

To reduce the attack surface, OpenSSH has been split into two separate source packages: openssh and openssh-gssapi.

  • openssh: Provides the default server and client binaries without GSSAPI or Kerberos support.
  • openssh-gssapi: Provides versions of the server and client that include GSSAPI/Kerberos support.

For new installations, the non-GSSAPI versions are now used by default. For existing systems, the Release Upgrader tool automatically detects whether GSSAPI is in use and selects the appropriate package to ensure continuity.

Improvements to Cryptography and Network Services

  • libp11 (v0.4.20): This update introduces support for post-quantum cryptographic algorithms, specifically ML-DSA, SLH-DSA, and FALCON for key generation and verification. It also adds support for OpenSSL 4.x as well as fixes related to concurrency.
  • Samba (v4.24.7): This version implements AES as the default encryption type for domains and now offers support for remote password management via Entra ID SSPR and Keycloak.
  • Postfix (v3.11.7): BerkeleyDB support for hash and B-tree map types is now deprecated. Additionally, tools such as postconf and postmap now support JSON output.
  • FreeRADIUS (v3.2.10):

Updates include the first implementation of “Protocol Failure” and the default suppression of secrets in new installations. - FRRouting (v10.7.1): New features include BFD authentication with Keychain support, as well as support for BGP IPv6 VTEP for EVPN.

Architecture-Specific Limitations

In the “cyrus-sasl2” package, the “libsasl2-modules-sql” binary no longer specifically supports the PostgreSQL database for the i386 architecture. This limitation does not affect other supported architectures.

Expansion of Hardware Platforms and RISC-V Support

Ubuntu 26.10 significantly expands its hardware compatibility by introducing official support for RVA23 RISC-V platforms. Specifically, the operating system now supports the SiFive BigSky platform and SpacemiT K3 boards, including the Pico-ITX and CoM260 kits. To make this possible, Ubuntu provides special desktop and Xubuntu minimal images for RISC-V that are also compatible with QEMU environments.