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Ubuntu Security Notice USN-8112-3
March 24, 2026

linux-azure, linux-azure-4.15 vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-azure-4.15: Linux kernel for Microsoft Azure Cloud systems
- linux-azure: Linux kernel for Microsoft Azure Cloud systems

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:
  - x86 architecture;
  - MMC subsystem;
  - Network drivers;
  - USB Device Class drivers;
  - BTRFS file system;
  - HFS+ file system;
  - XFRM subsystem;
  - IPv4 networking;
  - IPv6 networking;
  - MAC80211 subsystem;
  - Simplified Mandatory Access Control Kernel framework;
(CVE-2021-47599, CVE-2022-48875, CVE-2022-49267, CVE-2024-47659,
CVE-2024-49927, CVE-2024-56548, CVE-2024-56581, CVE-2024-56593,
CVE-2025-21704, CVE-2025-40215)

Update instructions:

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

Ubuntu 18.04 LTS
  linux-image-4.15.0-1197-azure   4.15.0-1197.212
                                  Available with Ubuntu Pro
  linux-image-azure-4.15          4.15.0.1197.165
                                  Available with Ubuntu Pro
  linux-image-azure-lts-18.04     4.15.0.1197.165
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  linux-image-4.15.0-1197-azure   4.15.0-1197.212~16.04.1
                                  Available with Ubuntu Pro
  linux-image-azure               4.15.0.1197.212~16.04.1
                                  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-8112-3
  https://ubuntu.com/security/notices/USN-8112-2
  https://ubuntu.com/security/notices/USN-8112-1
  CVE-2021-47599, CVE-2022-48875, CVE-2022-49267, CVE-2024-47659,
  CVE-2024-49927, CVE-2024-56548, CVE-2024-56581, CVE-2024-56593,
  CVE-2025-21704, CVE-2025-40215