========================================================================== Ubuntu Security Notice USN-7860-4 November 07, 2025
linux-intel-iot-realtime, linux-realtime vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 22.04 LTS
Summary:
The system could be made to expose sensitive information.
Software Description:
- linux-intel-iot-realtime: Linux kernel for Intel IoT Real-time platforms
- linux-realtime: Linux kernel for Real-time 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.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 22.04 LTS
linux-image-5.15.0-1088-intel-iot-realtime 5.15.0-1088.90
Available with Ubuntu Pro
linux-image-5.15.0-1095-realtime 5.15.0-1095.104
Available with Ubuntu Pro
linux-image-intel-iot-realtime 5.15.0.1088.92
Available with Ubuntu Pro
linux-image-intel-iot-realtime-5.15 5.15.0.1088.92
Available with Ubuntu Pro
linux-image-realtime 5.15.0.1095.99
Available with Ubuntu Pro
linux-image-realtime-5.15 5.15.0.1095.99
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-7860-4
https://ubuntu.com/security/notices/USN-7860-3
https://ubuntu.com/security/notices/USN-7860-2
https://ubuntu.com/security/notices/USN-7860-1
CVE-2025-40300
Package Information:
https://launchpad.net/ubuntu/+source/linux-intel-iot-realtime/5.15.0-1088.90
https://launchpad.net/ubuntu/+source/linux-realtime/5.15.0-1095.104
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