1. Ubuntu Security Notices
  2. USN-8255-2

USN-8255-2: Linux kernel (Azure) vulnerabilities

Publication date

11 May 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

Details

Stonejiajia, Shir Tamari and Sagi Tzadik discovered that the OverlayFS
implementation in the Ubuntu Linux kernel did not properly perform
permission checks in certain situations. A local attacker could possibly
use this to gain elevated privileges. (CVE-2023-2640)

Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in
the Ubuntu Linux kernel did not properly perform permission checks in
certain situations. A local attacker could possibly use this to gain
elevated privileges. (CVE-2023-32629)

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 drivers;
  • NVME drivers

Stonejiajia, Shir Tamari and Sagi Tzadik discovered that the OverlayFS
implementation in the Ubuntu Linux kernel did not properly perform
permission checks in certain situations. A local attacker could possibly
use this to gain elevated privileges. (CVE-2023-2640)

Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in
the Ubuntu Linux kernel did not properly perform permission checks in
certain situations. A local attacker could possibly use this to gain
elevated privileges. (CVE-2023-32629)

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 drivers;
  • NVME drivers

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
20.04 LTS focal linux-image-5.15.0-1111-azure –  5.15.0-1111.120~20.04.1  
linux-image-azure –  5.15.0.1111.120~20.04.1  
linux-image-azure-5.15 –  5.15.0.1111.120~20.04.1  
linux-image-azure-cvm –  5.15.0.1111.120~20.04.1  

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References

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