Ubuntu 25.04 USN-7860-1: Linux Kernel Critical Info Leak CVE-2025-40300

ubuntu

November 6, 2025

The system could be made to expose sensitive information.

Summary

The system could be made to expose sensitive information.

Software Description:

- linux: Linux kernel

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

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

- linux-oracle: Linux kernel for Oracle Cloud systems

- linux-raspi: Linux kernel for Raspberry Pi systems

- linux-realtime: Linux kernel for Real-time systems

- linux-aws-6.14: Linux kernel for Amazon Web Services (AWS) systems

- linux-gcp-6.14: Linux kernel for Google Cloud Platform (GCP) systems

- linux-oem-6.14: Linux kernel for OEM systems

- linux-oracle-6.14: Linux kernel for Oracle 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 informat...

Read the Full Advisory

Topics Covered

security advisory Ubuntu system update information exposure Linux kernel vmscape

Update Instructions

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

Ubuntu 25.04
   linux-image-6.14.0-1015-realtime  6.14.0-1015.15
   linux-image-6.14.0-1016-aws     6.14.0-1016.16
   linux-image-6.14.0-1016-aws-64k  6.14.0-1016.16
   linux-image-6.14.0-1016-oracle  6.14.0-1016.16
   linux-image-6.14.0-1016-oracle-64k  6.14.0-1016.16
   linux-image-6.14.0-1017-raspi   6.14.0-1017.17
   linux-image-6.14.0-1019-gcp     6.14.0-1019.20
   linux-image-6.14.0-1019-gcp-64k  6.14.0-1019.20
   linux-image-6.14.0-35-generic   6.14.0-35.35
   linux-image-6.14.0-35-generic-64k  6.14.0-35.35
   linux-image-aws                 6.14.0-1016.16
   linux-image-aws-6.14            6.14.0-1016.16
   linux-image-aws-64k             6.14.0-1016.16
   linux-image-aws-64k-6.14        6.14.0-1016.16
   linux-image-gcp                 6.14.0-1019.20
   linux-image-gcp-6.14            6.14.0-1019.20
   linux-image-gcp-64k             6.14.0-1019.20
   linux-image-gcp-64k-6.14        6.14.0-1019.20
   linux-image-generic             6.14.0-35.35
   linux-image-generic-6.14        6.14.0-35.35
   linux-image-generic-64k         6.14.0-35.35
   linux-image-generic-64k-6.14    6.14.0-35.35
   linux-image-oracle              6.14.0-1016.16
   linux-image-oracle-6.14         6.14.0-1016.16
   linux-image-oracle-64k          6.14.0-1016.16
   linux-image-oracle-64k-6.14     6.14.0-1016.16
   linux-image-raspi               6.14.0-1017.17
   linux-image-raspi-6.14          6.14.0-1017.17
   linux-image-realtime            6.14.0-1015.15
   linux-image-realtime-6.14       6.14.0-1015.15
   linux-image-virtual             6.14.0-35.35
   linux-image-virtual-6.14        6.14.0-35.35

Ubuntu 24.04 LTS
   linux-image-6.14.0-1015-oem     6.14.0-1015.15
   linux-image-6.14.0-1016-aws     6.14.0-1016.16~24.04.1
   linux-image-6.14.0-1016-aws-64k  6.14.0-1016.16~24.04.1
   linux-image-6.14.0-1016-oracle  6.14.0-1016.16~24.04.1
   linux-image-6.14.0-1016-oracle-64k  6.14.0-1016.16~24.04.1
   linux-image-6.14.0-1019-gcp     6.14.0-1019.20~24.04.1
   linux-image-6.14.0-1019-gcp-64k  6.14.0-1019.20~24.04.1
   linux-image-aws                 6.14.0-1016.16~24.04.1
   linux-image-aws-6.14            6.14.0-1016.16~24.04.1
   linux-image-aws-64k             6.14.0-1016.16~24.04.1
   linux-image-aws-64k-6.14        6.14.0-1016.16~24.04.1
   linux-image-gcp                 6.14.0-1019.20~24.04.1
   linux-image-gcp-6.14            6.14.0-1019.20~24.04.1
   linux-image-gcp-64k             6.14.0-1019.20~24.04.1
   linux-image-gcp-64k-6.14        6.14.0-1019.20~24.04.1
   linux-image-oem-24.04           6.14.0-1015.15
   linux-image-oem-24.04a          6.14.0-1015.15
   linux-image-oem-24.04b          6.14.0-1015.15
   linux-image-oem-24.04c          6.14.0-1015.15
   linux-image-oem-6.14            6.14.0-1015.15
   linux-image-oracle              6.14.0-1016.16~24.04.1
   linux-image-oracle-6.14         6.14.0-1016.16~24.04.1
   linux-image-oracle-64k          6.14.0-1016.16~24.04.1
   linux-image-oracle-64k-6.14     6.14.0-1016.16~24.04.1

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.