==========================================================================
Ubuntu Security Notice USN-8361-2
June 04, 2026

linux-fips vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS

Summary:

The system could be compromised under certain conditions.

Software Description:
- linux-fips: Linux kernel with FIPS

Details:

A security issue was discovered in the Linux kernel.
An attacker could possibly use this to compromise the system.
This update corrects flaws in the following subsystem:
   - Packet sockets;
(CVE-2026-31504)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.04 LTS
   linux-image-4.4.0-1125-fips     4.4.0-1125.132
                                   Available with Ubuntu Pro
   linux-image-fips                4.4.0.1125.127
                                   Available with Ubuntu Pro

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References:
   https://ubuntu.com/security/notices/USN-8361-2
   https://ubuntu.com/security/notices/USN-8361-1
   CVE-2026-31504

Package Information:
   https://launchpad.net/ubuntu/+source/linux-fips/4.4.0-1125.132