Ubuntu releases FIPS kernel updates for 22.04 LTS to address multiple vulnerabilities

Canonical has released security updates for the Linux kernel FIPS packages targeting Ubuntu 22.04 LTS. These updates address several vulnerabilities that could potentially allow an attacker to compromise a system. The fixes specifically target the linux-fips package and its associated image versions.

Users must perform a standard system update followed by a reboot to apply the changes. Notably, this update introduces an unavoidable Application Binary Interface (ABI) change. Consequently, any third-party kernel modules manually installed by the user will need to be recompiled and reinstalled to remain compatible with the new kernel version.

Vulnerability details and ABI impact

• Affected Subsystems: The security patches address flaws within the x86 architecture, hardware monitoring drivers, OCFS2 file system, IPv4 networking, Ethernet bridge, Netfilter, and the XFRM subsystem.
• Security Identifiers: The update resolves five specific vulnerabilities, identified as CVE-2025-21656, CVE-2026-63940, CVE-2026-74350, CVE-2026-98432, and CVE-2026-99999.
• Package Versions: For Ubuntu 22.04 LTS (Jammy), the update includes linux-image-5.15.0-203-fips (version 5.15.0-203.213+fips1) and linux-image-fips (version 5.15.0.203.117).
• ABI Change Requirement: Because the update changes the kernel ABI, users with non-standard kernel metapackages or custom third-party modules must manually recompile those modules to ensure system stability.

Why it matters

This update is critical for enterprise users relying on FIPS-140 certified environments for regulatory compliance. System administrators must be particularly cautious regarding the ABI change, as it necessitates manual intervention for any proprietary or out-of-tree drivers used in production environments.