--- title: 'USN-7860-4: Linux kernel (Real-time) vulnerability | Ubuntu security notices' description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/notices/USN-7860-4 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-7860-4 --- # USN-7860-4: Linux kernel (Real-time) vulnerability Publication date 7 November 2025 Overview The system could be made to expose sensitive information. Releases [22.04 LTS](https://ubuntu.com/security/notices?release=jammy) --- Open side navigation ## Packages * [linux-intel-iot-realtime](https://ubuntu.com/security/cves?package=linux-intel-iot-realtime) - Linux kernel for Intel IoT Real-time platforms * [linux-realtime](https://ubuntu.com/security/cves?package=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 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.](https://ubuntu.com/security/cves/about#security) 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 | | --- | --- | | 22.04 LTS jammy | [linux-image-5.15.0-1088-intel-iot-realtime](https://launchpad.net/ubuntu/+source/linux-signed-intel-iot-realtime) –  5.15.0-1088.90   Real-time | | | | [linux-image-5.15.0-1095-realtime](https://launchpad.net/ubuntu/+source/linux-signed-realtime) –  5.15.0-1095.104   Real-time | | | | [linux-image-intel-iot-realtime](https://launchpad.net/ubuntu/+source/linux-meta-intel-iot-realtime) –  5.15.0.1088.92   Real-time | | | | [linux-image-intel-iot-realtime-5.15](https://launchpad.net/ubuntu/+source/linux-meta-intel-iot-realtime) –  5.15.0.1088.92   Real-time | | | | [linux-image-realtime](https://launchpad.net/ubuntu/+source/linux-meta-realtime) –  5.15.0.1095.99   Real-time | | | | [linux-image-realtime-5.15](https://launchpad.net/ubuntu/+source/linux-meta-realtime) –  5.15.0.1095.99   Real-time | | | --- ### Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. [Get Ubuntu Pro](https://ubuntu.com/pro) ## References * [CVE-2025-40300](https://ubuntu.com/security/CVE-2025-40300) ## Related notices id="usn" *Search* * [USN-7940-1](https://ubuntu.com/security/notices/USN-7940-1) * [USN-7940-2](https://ubuntu.com/security/notices/USN-7940-2) * [USN-7939-1](https://ubuntu.com/security/notices/USN-7939-1) * [USN-7939-2](https://ubuntu.com/security/notices/USN-7939-2) * [USN-7938-1](https://ubuntu.com/security/notices/USN-7938-1) * [USN-7937-1](https://ubuntu.com/security/notices/USN-7937-1) * [USN-7935-1](https://ubuntu.com/security/notices/USN-7935-1) * [USN-7934-1](https://ubuntu.com/security/notices/USN-7934-1) * [USN-7933-1](https://ubuntu.com/security/notices/USN-7933-1) * [USN-7910-1](https://ubuntu.com/security/notices/USN-7910-1) --- Show 25 more references --- Have additional questions? [Talk to a member of the team ›](https://wiki.ubuntu.com/SecurityTeam/FAQ?_ga=2.242131138.1744859116.1742138161-1500419473.1726851136&_gl=1*161muja*_gcl_au*MzUyMTIzNjI1LjE3MzYyNDQ4NTE.#Contact)