1. Ubuntu Security Notices
  2. USN-8529-1

USN-8529-1: Linux kernel vulnerabilities

Publication date

10 July 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

Details

It was discovered that a logic flaw existed in the XFRM ESP-in-TCP
subsystem in the Linux kernel when handling socket buffer fragments. This
flaw is known as Fragnesia. A local attacker could use this to escalate
privileges, or possibly escape a container. (CVE-2026-43503)

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:

  • InfiniBand drivers;
  • SCSI subsystem;
  • Thermal drivers;
  • USB over IP driver;
  • Network file system (NFS) server daemon;
  • SMB network file system;
  • Tracing infrastructure;
  • B.A.T.M.A.N. meshing protocol;
  • Ethernet bridge;
  • Ceph Core library;
  • DCCP (Datagram Congestion Control Protocol);
  • IPv4 networking;
  • IPv6 networking;
  • Netfilter;
  • RxRPC session...

It was discovered that a logic flaw existed in the XFRM ESP-in-TCP
subsystem in the Linux kernel when handling socket buffer fragments. This
flaw is known as Fragnesia. A local attacker could use this to escalate
privileges, or possibly escape a container. (CVE-2026-43503)

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:

  • InfiniBand drivers;
  • SCSI subsystem;
  • Thermal drivers;
  • USB over IP driver;
  • Network file system (NFS) server daemon;
  • SMB network file system;
  • Tracing infrastructure;
  • B.A.T.M.A.N. meshing protocol;
  • Ethernet bridge;
  • Ceph Core library;
  • DCCP (Datagram Congestion Control Protocol);
  • IPv4 networking;
  • IPv6 networking;
  • Netfilter;
  • RxRPC session sockets;
  • X.25 network layer

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
18.04 LTS bionic linux-image-4.15.0-1149-fips –  4.15.0-1149.161  
linux-image-4.15.0-1156-oracle –  4.15.0-1156.167  
linux-image-4.15.0-1176-kvm –  4.15.0-1176.181  
linux-image-4.15.0-1187-gcp –  4.15.0-1187.204  
linux-image-4.15.0-1204-azure –  4.15.0-1204.219  
linux-image-4.15.0-2095-gcp-fips –  4.15.0-2095.101  
linux-image-4.15.0-2112-azure-fips –  4.15.0-2112.118  
linux-image-4.15.0-253-generic –  4.15.0-253.265  
linux-image-4.15.0-253-lowlatency –  4.15.0-253.265  
linux-image-azure-4.15 –  4.15.0.1204.172  
linux-image-azure-fips –  4.15.0.2112.108  
linux-image-azure-fips-4.15 –  4.15.0.2112.108  
linux-image-azure-lts-18.04 –  4.15.0.1204.172  
linux-image-fips –  4.15.0.1149.146  
linux-image-gcp-4.15 –  4.15.0.1187.200  
linux-image-gcp-fips –  4.15.0.2095.93  
linux-image-gcp-fips-4.15 –  4.15.0.2095.93  
linux-image-gcp-lts-18.04 –  4.15.0.1187.200  
linux-image-generic –  4.15.0.253.237  
linux-image-kvm –  4.15.0.1176.167  
linux-image-lowlatency –  4.15.0.253.237  
linux-image-oracle-4.15 –  4.15.0.1156.161  
linux-image-oracle-lts-18.04 –  4.15.0.1156.161  
linux-image-virtual –  4.15.0.253.237  

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References

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