1. Ubuntu Security Notices
  2. USN-8390-1

USN-8390-1: Linux kernel vulnerability

Publication date

4 June 2026

Overview

The system could be made to run programs as an administrator.

Releases

Packages

Details

It was discovered that the Linux kernel did not properly handle shared page
fragments during socket buffer operations, collectively known as Dirty
Frag. A logic flaw existed in the XFRM ESP-in-TCP subsystem and in the
RxRPC networking subsystem when processing paged fragments. A local
attacker could use this to escalate privileges, or possibly escape a
container.

It was discovered that the Linux kernel did not properly handle shared page
fragments during socket buffer operations, collectively known as Dirty
Frag. A logic flaw existed in the XFRM ESP-in-TCP subsystem and in the
RxRPC networking subsystem when processing paged fragments. A local
attacker could use this to escalate privileges, or possibly escape a
container.

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-4.15.0-1148-fips –  4.15.0-1148.160  
linux-image-4.15.0-1155-oracle –  4.15.0-1155.166  
linux-image-4.15.0-1175-kvm –  4.15.0-1175.180  
linux-image-4.15.0-1186-gcp –  4.15.0-1186.203  
linux-image-4.15.0-1202-azure –  4.15.0-1202.217  
linux-image-4.15.0-2094-gcp-fips –  4.15.0-2094.100  
linux-image-4.15.0-2111-azure-fips –  4.15.0-2111.117  
linux-image-4.15.0-251-generic –  4.15.0-251.263  
linux-image-4.15.0-251-lowlatency –  4.15.0-251.263  
linux-image-azure-4.15 –  4.15.0.1202.170  
linux-image-azure-fips –  4.15.0.2111.107  
linux-image-azure-fips-4.15 –  4.15.0.2111.107  
linux-image-azure-lts-18.04 –  4.15.0.1202.170  
linux-image-fips –  4.15.0.1148.145  
linux-image-gcp-4.15 –  4.15.0.1186.199  
linux-image-gcp-fips –  4.15.0.2094.92  
linux-image-gcp-fips-4.15 –  4.15.0.2094.92  
linux-image-gcp-lts-18.04 –  4.15.0.1186.199  
linux-image-generic –  4.15.0.251.235  
linux-image-kvm –  4.15.0.1175.166  
linux-image-lowlatency –  4.15.0.251.235  
linux-image-oracle-4.15 –  4.15.0.1155.160  
linux-image-oracle-lts-18.04 –  4.15.0.1155.160  
linux-image-virtual –  4.15.0.251.235  
14.04 LTS trusty linux-image-4.15.0-1202-azure –  4.15.0-1202.217~14.04.1  
linux-image-azure –  4.15.0.1202.217~14.04.1  

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References

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