1. Ubuntu Security Notices
  2. USN-8266-1

USN-8266-1: Linux kernel vulnerabilities

Publication date

11 May 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-aws-fips - Linux kernel for Amazon Web Services (AWS) systems with FIPS
  • linux-aws-hwe - Linux kernel for Amazon Web Services (AWS-HWE) systems
  • linux-azure-4.15 - Linux kernel for Microsoft Azure Cloud systems
  • linux-fips - Linux kernel with FIPS
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-4.15 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-fips - Linux kernel for Google Cloud Platform (GCP) systems with FIPS
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems

Details

Qualys discovered that several vulnerabilities existed in the AppArmor
Linux kernel Security Module (LSM). An unprivileged local attacker could
use these issues to load, replace, and remove arbitrary AppArmor profiles
causing denial of service, exposure of sensitive information (kernel
memory), local privilege escalation, or possibly escape a container.
(LP: #2143853, CVE-2026-23268, CVE-2026-23269, CVE-2026-23403,
CVE-2026-23404, CVE-2026-23405, CVE-2026-23410, CVE-2026-23411)

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:

  • GPU...

Qualys discovered that several vulnerabilities existed in the AppArmor
Linux kernel Security Module (LSM). An unprivileged local attacker could
use these issues to load, replace, and remove arbitrary AppArmor profiles
causing denial of service, exposure of sensitive information (kernel
memory), local privilege escalation, or possibly escape a container.
(LP: #2143853, CVE-2026-23268, CVE-2026-23269, CVE-2026-23403,
CVE-2026-23404, CVE-2026-23405, CVE-2026-23410, CVE-2026-23411)

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:

  • GPU drivers;
  • Network drivers;
  • Sun RPC protocol;
  • XFRM subsystem

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
18.04 LTS bionic linux-image-4.15.0-1146-fips –  4.15.0-1146.158  
linux-image-4.15.0-1153-oracle –  4.15.0-1153.164  
linux-image-4.15.0-1173-kvm –  4.15.0-1173.178  
linux-image-4.15.0-1184-gcp –  4.15.0-1184.201  
linux-image-4.15.0-1191-aws –  4.15.0-1191.204  
linux-image-4.15.0-1200-azure –  4.15.0-1200.215  
linux-image-4.15.0-2092-gcp-fips –  4.15.0-2092.98  
linux-image-4.15.0-2129-aws-fips –  4.15.0-2129.135  
linux-image-4.15.0-249-generic –  4.15.0-249.261  
linux-image-4.15.0-249-lowlatency –  4.15.0-249.261  
linux-image-aws-4.15 –  4.15.0.1191.189  
linux-image-aws-fips –  4.15.0.2129.123  
linux-image-aws-fips-4.15 –  4.15.0.2129.123  
linux-image-aws-lts-18.04 –  4.15.0.1191.189  
linux-image-azure-4.15 –  4.15.0.1200.168  
linux-image-azure-lts-18.04 –  4.15.0.1200.168  
linux-image-fips –  4.15.0.1146.143  
linux-image-gcp-4.15 –  4.15.0.1184.197  
linux-image-gcp-fips –  4.15.0.2092.90  
linux-image-gcp-fips-4.15 –  4.15.0.2092.90  
linux-image-gcp-lts-18.04 –  4.15.0.1184.197  
linux-image-generic –  4.15.0.249.233  
linux-image-kvm –  4.15.0.1173.164  
linux-image-lowlatency –  4.15.0.249.233  
linux-image-oracle-4.15 –  4.15.0.1153.158  
linux-image-oracle-lts-18.04 –  4.15.0.1153.158  
linux-image-virtual –  4.15.0.249.233  
16.04 LTS xenial linux-image-4.15.0-1184-gcp –  4.15.0-1184.201~16.04.1  
linux-image-4.15.0-1191-aws –  4.15.0-1191.204~16.04.1  
linux-image-4.15.0-249-generic –  4.15.0-249.261~16.04.1  
linux-image-4.15.0-249-lowlatency –  4.15.0-249.261~16.04.1  
linux-image-aws-hwe –  4.15.0.1191.204~16.04.1  
linux-image-gcp –  4.15.0.1184.201~16.04.1  
linux-image-generic-hwe-16.04 –  4.15.0.249.261~16.04.1  
linux-image-gke –  4.15.0.1184.201~16.04.1  
linux-image-lowlatency-hwe-16.04 –  4.15.0.249.261~16.04.1  
linux-image-oem –  4.15.0.249.261~16.04.1  
linux-image-virtual-hwe-16.04 –  4.15.0.249.261~16.04.1  

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References

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