USN-7935-1: Linux kernel (Azure) vulnerabilities

USN-7935-1: Linux kernel (Azure) vulnerabilities

Publication date : 15 December 2025
Overview: Several security issues were fixed in the Linux kernel.

Packages
linux-azure - Linux kernel for Microsoft Azure Cloud systems
linux-azure-6.8 - Linux kernel for Microsoft Azure cloud systems

Details
Jean-Claude Graf, Sandro Rüegge, Ali Hajiabadi, and Kaveh Razavi discovered
that the Linux kernel contained insufficient branch predictor isolation
between a guest and a userspace hypervisor for certain processors. This
flaw is known as VMSCAPE. An attacker in a guest VM could possibly use this
to expose sensitive information from the host OS. (CVE-2025-40300)

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:

• Cryptographic API;
• HSI subsystem;
• Media drivers;
• Network drivers;
• Bluetooth subsystem;
• Timer subsystem;
• Memory management;
• Appletalk network protocol;
• Netfilter;
• TLS protocol

Update instructions
After a standard system update you need to reboot your computer to make all the necessary changes.
The problem can be corrected by updating your system to the following package versions:

24.04 LTS noble

• linux-image-6.8.0-1044-azure – 6.8.0-1044.50
• linux-image-azure-6.8 – 6.8.0-1044.50
• linux-image-azure-lts-24.04 – 6.8.0-1044.50

22.04 LTS jammy

• linux-image-6.8.0-1044-azure – 6.8.0-1044.50~22.04.1
• linux-image-azure – 6.8.0-1044.50~22.04.1
• linux-image-azure-6.8 – 6.8.0-1044.50~22.04.1