Ubuntu Security Notices USN-8361-2 USN-8361-2: Linux kernel (FIPS) vulnerability Publication date 4 June 2026 Overview The system could be compromised under certain conditions. Releases 16.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Related notices Packages 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 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 Update instructions After a standard system update you need to reboot your computer to make all the necessary changes. Learn more about how to get the fixes. 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. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 16.04 LTS xenial linux-image-4.4.0-1125-fips – 4.4.0-1125.132 FIPS Updates FIPS-140 certified package with security fixes. Available with Ubuntu Pro. linux-image-fips – 4.4.0.1125.127 FIPS Updates FIPS-140 certified package with security fixes. Available with Ubuntu Pro. Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-31504 CVE-2026-31504 Related notices USN-8393-1 USN-8392-1 USN-8391-1 USN-8374-1 USN-8361-1 USN-8351-1 USN-8350-1 USN-8310-1 USN-8305-1 USN-8305-2 USN-8393-1 USN-8392-1 USN-8391-1 USN-8374-1 USN-8361-1 USN-8351-1 USN-8350-1 USN-8310-1 USN-8305-1 USN-8305-2 USN-8289-1 USN-8289-2 USN-8281-1 USN-8281-2 USN-8280-1 USN-8280-2 USN-8280-3 USN-8279-1 USN-8279-2 USN-8279-3 USN-8278-1 USN-8278-2 USN-8277-1 USN-8277-2 Show 14 more references Show less references Have additional questions? Talk to a member of the team ›