========================================================================== Ubuntu Security Notice USN-8390-2 June 17, 2026
linux-azure, linux-gcp, linux-hwe, linux-oracle vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 LTS
Summary:
The system could be made to run programs as an administrator.
Software Description:
- linux-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-hwe: Linux hardware enablement (HWE) kernel
- linux-oracle: Linux kernel for Oracle Cloud systems
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.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 16.04 LTS
linux-image-4.15.0-1155-oracle 4.15.0-1155.166~16.04.1
Available with Ubuntu Pro
linux-image-4.15.0-1186-gcp 4.15.0-1186.203~16.04.1
Available with Ubuntu Pro
linux-image-4.15.0-1202-azure 4.15.0-1202.217~16.04.1
Available with Ubuntu Pro
linux-image-4.15.0-251-generic 4.15.0-251.263~16.04.1
Available with Ubuntu Pro
linux-image-4.15.0-251-lowlatency 4.15.0-251.263~16.04.1
Available with Ubuntu Pro
linux-image-azure 4.15.0.1202.217~16.04.1
Available with Ubuntu Pro
linux-image-gcp 4.15.0.1186.203~16.04.1
Available with Ubuntu Pro
linux-image-generic-hwe-16.04 4.15.0.251.263~16.04.1
Available with Ubuntu Pro
linux-image-gke 4.15.0.1186.203~16.04.1
Available with Ubuntu Pro
linux-image-lowlatency-hwe-16.04 4.15.0.251.263~16.04.1
Available with Ubuntu Pro
linux-image-oem 4.15.0.251.263~16.04.1
Available with Ubuntu Pro
linux-image-oracle 4.15.0.1155.166~16.04.1
Available with Ubuntu Pro
linux-image-virtual-hwe-16.04 4.15.0.251.263~16.04.1
Available with Ubuntu Pro
After a standard system update you need to reboot your computer to make
all the necessary changes.
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.
References:
https://ubuntu.com/security/notices/USN-8390-2
https://ubuntu.com/security/notices/USN-8390-1
CVE-2026-43284
OpenPGP_signature.asc
Description: OpenPGP digital signature
