USN-8959-1: Ubuntu patches Linux kernel on 26.04 and 24.04, ABI change

Canonical released security advisory USN-8959-1 on 3 November 2026, addressing multiple vulnerabilities in the Linux kernel on Ubuntu 26.04 LTS and 24.04 LTS. Administrators running VPS or dedicated servers on these two versions must schedule a reboot and, if using third-party kernel modules, a recompilation.\n\n## What's changing\n\nThe advisory affects the linux, linux-aws, linux-gcp, linux-hwe-7.0, linux-ibm and linux-oracle packages. It resolves several security issues in the Linux kernel across linux packages for Amazon Web Services, Google Cloud Platform, linux-hwe-7.0, IBM Cloud and Oracle Cloud. The vulnerabilities span dozens of subsystems, including memory management, filesystems (Btrfs, XFS, Ext4, NFS), IPv4/IPv6 networking stack, Bluetooth, KVM and the Netfilter module.\n\nAn attacker exploiting these flaws could compromise the system. External analyses based on the same advisory report a CVSS 3.1 score ranging from 7.8 to 10, indicating that some of the patched vulnerabilities are considered critical.\n\n## The note you cannot skip: ABI change\n\nCanonical explicitly notes that the update entails an unavoidable ABI change. Anyone running third-party kernel modules—proprietary drivers, DKMS modules for storage or virtualisation—must recompile and reinstall them after the update, unless the system uses standard metapackages (linux-generic, linux-virtual and similar), in which case the operation happens automatically during the upgrade.\n\n## Patched versions\n\n| Release | Package | Version |\n|---|---|---|\n| 26.04 LTS (resolute) | linux-image-generic | 7.0.0-42.42 |\n| 26.04 LTS (resolute) | linux-image-aws | 7.0.0-1016.17 |\n| 26.04 LTS (resolute) | linux-image-gcp | 7.0.0-1016.18 |\n| 26.04 LTS (resolute) | linux-image-ibm | 7.0.0-1017.17 |\n| 26.04 LTS (resolute) | linux-image-oracle | 7.0.0-1015.16 |\n| 24.04 LTS (noble) | linux-image-generic (via HWE) | 7.0.0-42.42~24.04.1 |\n\nKernel series 7.0 is not a standalone novelty: it is the same line introduced with Ubuntu 26.04 LTS release on 23 April 2026, and is now reaching 24.04 LTS through the Hardware Enablement stack.\n\nApplying the patch requires a standard update (apt update && apt upgrade) followed by a system reboot. Administrators managing VPS fleets with custom modules should verify compatibility before rolling out the update to production.\n