1. Ubuntu Security Notices
  2. USN-8566-1

USN-8566-1: Linux kernel vulnerabilities

Publication date

20 July 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux - Linux kernel
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke - Linux kernel for Google Container Engine (GKE) systems
  • linux-realtime - Linux kernel for Real-time systems

Details

It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)

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:

  • PSP security protocol;
  • ARM64 architecture;
  • PowerPC architecture;
  • RISC-V architecture;
  • S390 architecture;
  • User-Mode Linux (UML);
  • x86 architecture;
  • Block layer subsystem;
  • Cryptographic API;
  • Intel NPU Driver;
  • DRBD Distributed Replicated Block Device drivers;
  • Ublk userspace block driver;
  • Bluetooth drivers;
  • Bus devices;
  • Character...

It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)

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:

  • PSP security protocol;
  • ARM64 architecture;
  • PowerPC architecture;
  • RISC-V architecture;
  • S390 architecture;
  • User-Mode Linux (UML);
  • x86 architecture;
  • Block layer subsystem;
  • Cryptographic API;
  • Intel NPU Driver;
  • DRBD Distributed Replicated Block Device drivers;
  • Ublk userspace block driver;
  • Bluetooth drivers;
  • Bus devices;
  • Character device driver;
  • Clock framework and drivers;
  • CPU frequency scaling framework;
  • Hardware crypto device drivers;
  • EDAC drivers;
  • EFI core;
  • FWCTL subsystem;
  • GPU drivers;
  • HID subsystem;
  • I3C subsystem;
  • InfiniBand drivers;
  • IOMMU subsystem;
  • Mailbox framework;
  • Multiple devices driver;
  • Media drivers;
  • NVIDIA Tegra memory controller driver;
  • MTD block device drivers;
  • Network drivers;
  • Ethernet bonding driver;
  • Mellanox network drivers;
  • Microsoft Azure Network Adapter (MANA) driver;
  • STMicroelectronics network drivers;
  • MediaTek network drivers;
  • NVME drivers;
  • PCI subsystem;
  • Pin controllers subsystem;
  • Chrome hardware platform drivers;
  • ACPI WMI driver;
  • x86 platform drivers;
  • Generic PM domains;
  • MediaTek PM domains;
  • Power supply drivers;
  • MPAM driver;
  • Amlogic Meson reset controller drivers;
  • S/390 drivers;
  • SCSI subsystem;
  • NVIDIA Tegra Control Backbone (CBB) driver;
  • SPI subsystem;
  • Greybus lights staging drivers;
  • Media staging drivers;
  • Realtek RTL8723BS SDIO drivers;
  • TCM subsystem;
  • TTY drivers;
  • USB Device Class drivers;
  • ULPI bus;
  • USB Type-C support driver;
  • TI TPS6598x USB Power Delivery controller driver;
  • vDPA drivers;
  • VFIO drivers;
  • Framebuffer layer;
  • TSM AMD SEV Guest driver;
  • Xen hypervisor drivers;
  • File systems infrastructure;
  • BTRFS file system;
  • Ceph distributed file system;
  • EROFS file system;
  • F2FS file system;
  • FUSE (File system in Userspace);
  • GFS2 file system;
  • HFS+ file system;
  • HugeTLB file system;
  • Network file system (NFS) server daemon;
  • NILFS2 file system;
  • File system notification infrastructure;
  • NTFS3 file system;
  • OCFS2 file system;
  • Overlay file system;
  • Diskquota system;
  • SMB network file system;
  • Tracing file system;
  • DRM TTM subsystem;
  • Control group (cgroup);
  • Kernel CPU control infrastructure;
  • QorIQ DPAA2 FSL-MC bus driver;
  • Freescale ENETC Ethernet drivers;
  • Memory Management;
  • padata parallel execution mechanism;
  • PPP protocol drivers and compressors;
  • Bluetooth subsystem;
  • Networking core;
  • Netfilter;
  • Network traffic control;
  • io_uring subsystem;
  • IPC subsystem;
  • Audit subsystem;
  • BPF subsystem;
  • Kernel exit() syscall;
  • Kernel fork() syscall;
  • Kernel futex primitives;
  • Padata parallel execution mechanism;
  • Scheduler infrastructure;
  • Tracing infrastructure;
  • Cryptographic library;
  • Memory management;
  • 802.1Q VLAN protocol;
  • B.A.T.M.A.N. meshing protocol;
  • Ethernet bridge;
  • Ceph Core library;
  • Distributed Switch Architecture;
  • IPv4 networking;
  • IPv6 networking;
  • MAC80211 subsystem;
  • Multipath TCP;
  • Open vSwitch;
  • Phonet protocol;
  • RDS protocol;
  • SCTP protocol;
  • SMC sockets;
  • TIPC protocol;
  • TLS protocol;
  • Unix domain sockets;
  • VMware vSockets driver;
  • XFRM subsystem;
  • Integrity Measurement Architecture(IMA) framework;
  • SELinux security module;
  • ALSA framework;
  • HD-audio driver;
  • QCOM ASoC drivers;
  • SOF drivers;
  • STI ASoC drivers;
  • USB sound devices;
  • KVM subsystem

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
26.04 LTS resolute linux-image-7.0.0-1003-gke –  7.0.0-1003.4
linux-image-7.0.0-1003-gke-64k –  7.0.0-1003.4
linux-image-7.0.0-1008-gcp –  7.0.0-1008.8
linux-image-7.0.0-1008-gcp-64k –  7.0.0-1008.8
linux-image-7.0.0-28-generic –  7.0.0-28.28
linux-image-7.0.0-28-generic-64k –  7.0.0-28.28
linux-image-7.0.0-28-realtime –  7.0.0-28.28.1
linux-image-7.0.0-28-realtime-64k –  7.0.0-28.28.1
linux-image-gcp –  7.0.0-1008.8
linux-image-gcp-64k –  7.0.0-1008.8
linux-image-gcp-64k-7.0 –  7.0.0-1008.8
linux-image-gcp-7.0 –  7.0.0-1008.8
linux-image-generic –  7.0.0-28.28
linux-image-generic-64k –  7.0.0-28.28
linux-image-generic-64k-7.0 –  7.0.0-28.28
linux-image-generic-64k-hwe-26.04 –  7.0.0-28.28
linux-image-generic-7.0 –  7.0.0-28.28
linux-image-generic-hwe-26.04 –  7.0.0-28.28
linux-image-gke –  7.0.0-1003.4
linux-image-gke-64k –  7.0.0-1003.4
linux-image-gke-64k-7.0 –  7.0.0-1003.4
linux-image-gke-64k-hwe-26.04 –  7.0.0-1003.4
linux-image-gke-7.0 –  7.0.0-1003.4
linux-image-gke-hwe-26.04 –  7.0.0-1003.4
linux-image-oem-24.04 –  7.0.0-28.28
linux-image-oem-24.04a –  7.0.0-28.28
linux-image-oem-24.04b –  7.0.0-28.28
linux-image-oem-24.04c –  7.0.0-28.28
linux-image-oem-24.04d –  7.0.0-28.28
linux-image-realtime –  7.0.0-28.28.1
linux-image-realtime-64k –  7.0.0-28.28.1
linux-image-realtime-64k-7.0 –  7.0.0-28.28.1
linux-image-realtime-64k-hwe-26.04 –  7.0.0-28.28.1
linux-image-realtime-7.0 –  7.0.0-28.28.1
linux-image-realtime-hwe-26.04 –  7.0.0-28.28.1
linux-image-virtual –  7.0.0-28.28
linux-image-virtual-7.0 –  7.0.0-28.28
linux-image-virtual-hwe-26.04 –  7.0.0-28.28

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References

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