Home / mailings [USN-8819-4] Linux kernel (FIPS) vulnerabilities
Posted on 30 September 2026
Ubuntu Security==========================================================================Ubuntu Security Notice USN-8819-4
September 30, 2026
linux-aws-fips, linux-azure-fips, linux-fips vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description:
- linux-aws-fips: Linux kernel for Amazon Web Services (AWS) systems with FIPS
- linux-azure-fips: Linux kernel for Microsoft Azure Cloud systems with FIPS
- linux-fips: Linux kernel with FIPS
Details:
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Network file system (NFS) server daemon;
- IPv6 networking;
- Netfilter;
(CVE-2025-38724, CVE-2026-53131, CVE-2026-53221)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 18.04 LTS
linux-image-4.15.0-1152-fips 4.15.0-1152.164+1
Available with Ubuntu Pro
linux-image-4.15.0-2115-azure-fips 4.15.0-2115.121
Available with Ubuntu Pro
linux-image-4.15.0-2135-aws-fips 4.15.0-2135.141
Available with Ubuntu Pro
linux-image-aws-fips 4.15.0.2135.129
Available with Ubuntu Pro
linux-image-aws-fips-4.15 4.15.0.2135.129
Available with Ubuntu Pro
linux-image-azure-fips 4.15.0.2115.111
Available with Ubuntu Pro
linux-image-azure-fips-4.15 4.15.0.2115.111
Available with Ubuntu Pro
linux-image-fips 4.15.0.1152.150
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-8819-4
https://ubuntu.com/security/notices/USN-8819-3
https://ubuntu.com/security/notices/USN-8819-2
https://ubuntu.com/security/notices/USN-8819-1
CVE-2025-38724, CVE-2026-53131, CVE-2026-53221
Package Information:
https://launchpad.net/ubuntu/+source/linux-aws-fips/4.15.0-2135.141
https://launchpad.net/ubuntu/+source/linux-azure-fips/4.15.0-2115.121
https://launchpad.net/ubuntu/+source/linux-fips/4.15.0-1152.164
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