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Ubuntu 18.04 LTS USN-8266-1 Critical Kernel DoS Escalation CVE-2026-23268

ubuntu
Calendar Grey May 11, 2026
Dist Ubuntu Esm H88
Several issues in Ubuntu 18.04 and 16.04 kernels addressed for local privilege escalation risks. Update now!
Several security issues were fixed in the Linux kernel.

Summary

Several security issues were fixed in the Linux kernel.

Software Description:

- 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-azure-4.15: Linux kernel for Microsoft Azure Cloud systems

- linux-fips: Linux kernel with FIPS

- 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-kvm: Linux kernel for cloud environments

- linux-oracle: Linux kernel for Oracle Cloud systems

- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems

- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems

- linux-hwe: Linux hardware enablement (HWE) kernel

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 ar...

Read the Full Advisory

Topics%20covered

Topics Covered

security advisory denial of service critical local privilege escalation Ubuntu kernel

Update Instructions

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

Ubuntu 18.04 LTS
  linux-image-4.15.0-1146-fips    4.15.0-1146.158
                                  Available with Ubuntu Pro
  linux-image-4.15.0-1153-oracle  4.15.0-1153.164
                                  Available with Ubuntu Pro
  linux-image-4.15.0-1173-kvm     4.15.0-1173.178
                                  Available with Ubuntu Pro
  linux-image-4.15.0-1184-gcp     4.15.0-1184.201
                                  Available with Ubuntu Pro
  linux-image-4.15.0-1191-aws     4.15.0-1191.204
                                  Available with Ubuntu Pro
  linux-image-4.15.0-1200-azure   4.15.0-1200.215
                                  Available with Ubuntu Pro
  linux-image-4.15.0-2092-gcp-fips  4.15.0-2092.98
                                  Available with Ubuntu Pro
  linux-image-4.15.0-2129-aws-fips  4.15.0-2129.135
                                  Available with Ubuntu Pro
  linux-image-4.15.0-249-generic  4.15.0-249.261
                                  Available with Ubuntu Pro
  linux-image-4.15.0-249-lowlatency  4.15.0-249.261
                                  Available with Ubuntu Pro
  linux-image-aws-4.15            4.15.0.1191.189
                                  Available with Ubuntu Pro
  linux-image-aws-fips            4.15.0.2129.123
                                  Available with Ubuntu Pro
  linux-image-aws-fips-4.15       4.15.0.2129.123
                                  Available with Ubuntu Pro
  linux-image-aws-lts-18.04       4.15.0.1191.189
                                  Available with Ubuntu Pro
  linux-image-azure-4.15          4.15.0.1200.168
                                  Available with Ubuntu Pro
  linux-image-azure-lts-18.04     4.15.0.1200.168
                                  Available with Ubuntu Pro
  linux-image-fips                4.15.0.1146.143
                                  Available with Ubuntu Pro
  linux-image-gcp-4.15            4.15.0.1184.197
                                  Available with Ubuntu Pro
  linux-image-gcp-fips            4.15.0.2092.90
                                  Available with Ubuntu Pro
  linux-image-gcp-fips-4.15       4.15.0.2092.90
                                  Available with Ubuntu Pro
  linux-image-gcp-lts-18.04       4.15.0.1184.197
                                  Available with Ubuntu Pro
  linux-image-generic             4.15.0.249.233
                                  Available with Ubuntu Pro
  linux-image-kvm                 4.15.0.1173.164
                                  Available with Ubuntu Pro
  linux-image-lowlatency          4.15.0.249.233
                                  Available with Ubuntu Pro
  linux-image-oracle-4.15         4.15.0.1153.158
                                  Available with Ubuntu Pro
  linux-image-oracle-lts-18.04    4.15.0.1153.158
                                  Available with Ubuntu Pro
  linux-image-virtual             4.15.0.249.233
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  linux-image-4.15.0-1184-gcp     4.15.0-1184.201~16.04.1
                                  Available with Ubuntu Pro
  linux-image-4.15.0-1191-aws     4.15.0-1191.204~16.04.1
                                  Available with Ubuntu Pro
  linux-image-4.15.0-249-generic  4.15.0-249.261~16.04.1
                                  Available with Ubuntu Pro
  linux-image-4.15.0-249-lowlatency  4.15.0-249.261~16.04.1
                                  Available with Ubuntu Pro
  linux-image-aws-hwe             4.15.0.1191.204~16.04.1
                                  Available with Ubuntu Pro
  linux-image-gcp                 4.15.0.1184.201~16.04.1
                                  Available with Ubuntu Pro
  linux-image-generic-hwe-16.04   4.15.0.249.261~16.04.1
                                  Available with Ubuntu Pro
  linux-image-gke                 4.15.0.1184.201~16.04.1
                                  Available with Ubuntu Pro
  linux-image-lowlatency-hwe-16.04  4.15.0.249.261~16.04.1
                                  Available with Ubuntu Pro
  linux-image-oem                 4.15.0.249.261~16.04.1
                                  Available with Ubuntu Pro
  linux-image-virtual-hwe-16.04   4.15.0.249.261~16.04.1
                                  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-8266-1

https://launchpad.net/bugs/2143853

CVE-2024-27388, CVE-2024-46816, CVE-2024-49938, CVE-2024-50008,

CVE-2024-50142, CVE-2026-23209, CVE-2026-23268, CVE-2026-23269,

CVE-2026-23403, CVE-2026-23404, CVE-2026-23405, CVE-2026-23410,

CVE-2026-23411

Severity
critical
Lowest
Low
Medium
High
Critical

Ubuntu Security Notice USN-8266-1

Topics%20covered

Topics Covered

security advisory denial of service critical local privilege escalation Ubuntu kernel

Package Information

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