1. Ubuntu Security Notices
  2. USN-8667-1

USN-8667-1: Linux kernel (KVM) vulnerabilities

Publication date

21 August 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux-kvm - Linux kernel for cloud environments

Details

Siebe Devroe, Héloïse Gollier, and Mathy Vanhoef discovered that the WiFi
implementation in the Linux kernel did not properly handle aggregated
frames in mesh networks, due to an incorrect fix for CVE-2020-24588. A
physically proximate attacker could use this issue to inject packets.
(CVE-2025-27558)

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;
  • Cryptographic API;
  • InfiniBand drivers;
  • Media drivers;
  • NVIDIA Tegra memory controller driver;
  • Network drivers;
  • NVME drivers;
  • File systems infrastructure;
  • Ext4 file system;
  • Network file system (NFS) server daemon;
  • IPv4 networking;
  • Network traffic control;
  • TCP...

Siebe Devroe, Héloïse Gollier, and Mathy Vanhoef discovered that the WiFi
implementation in the Linux kernel did not properly handle aggregated
frames in mesh networks, due to an incorrect fix for CVE-2020-24588. A
physically proximate attacker could use this issue to inject packets.
(CVE-2025-27558)

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;
  • Cryptographic API;
  • InfiniBand drivers;
  • Media drivers;
  • NVIDIA Tegra memory controller driver;
  • Network drivers;
  • NVME drivers;
  • File systems infrastructure;
  • Ext4 file system;
  • Network file system (NFS) server daemon;
  • IPv4 networking;
  • Network traffic control;
  • TCP network protocol;
  • Tracing infrastructure;
  • Locking primitives;
  • B.A.T.M.A.N. meshing protocol;
  • Ceph Core library;
  • IPv6 networking;
  • Multipath TCP;
  • Netfilter;
  • RxRPC session sockets;
  • SCTP protocol;
  • SMC sockets;
  • TIPC protocol

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.

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
20.04 LTS focal linux-image-5.4.0-1149-kvm –  5.4.0-1149.158  
linux-image-kvm –  5.4.0.1149.145  
linux-image-kvm-5.4 –  5.4.0.1149.145  

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References

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