Ubuntu 18.04 LTS Linux Kernel Security Flaw Privilege Escalation USN-8392-1
ubuntu
June 4, 2026
Several security issues were fixed in the Linux kernel.
Summary
Several security issues were fixed in the Linux kernel.
Software Description:
- linux-aws-5.4: Linux kernel for Amazon Web Services (AWS) systems
- linux-hwe-5.4: Linux hardware enablement (HWE) kernel
Details:
It was discovered that the Linux kernel algif_aead module did not properly
handle in-place cryptographic operations. This flaw is known as Copy Fail.
A local attacker could use this to escalate privileges, or possibly escape
a container. (CVE-2026-31431)
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. (CVE-2026-43284, CVE-2026-43500)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
Th...
Topics Covered
Update Instructions
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 18.04 LTS
linux-image-5.4.0-1160-aws 5.4.0-1160.170~18.04.1
Available with Ubuntu Pro
linux-image-5.4.0-231-generic 5.4.0-231.251~18.04.1
Available with Ubuntu Pro
linux-image-5.4.0-231-lowlatency 5.4.0-231.251~18.04.1
Available with Ubuntu Pro
linux-image-aws 5.4.0.1160.170~18.04.1
Available with Ubuntu Pro
linux-image-aws-5.4 5.4.0.1160.170~18.04.1
Available with Ubuntu Pro
linux-image-generic-5.4 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-generic-hwe-18.04 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-lowlatency-5.4 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-lowlatency-hwe-18.04 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-oem 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-oem-osp1 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-snapdragon-5.4 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-snapdragon-hwe-18.04 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-virtual-5.4 5.4.0.231.251~18.04.1
Available with Ubuntu Pro
linux-image-virtual-hwe-18.04 5.4.0.231.251~18.04.1
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-8392-1
CVE-2026-31431, CVE-2026-31504, CVE-2026-31533, CVE-2026-43033,
CVE-2026-43077, CVE-2026-43078, CVE-2026-43284, CVE-2026-43494,
CVE-2026-43500, CVE-2026-46028
PREVIOUS
NEXT
Severity
critical
Lowest
Low
Medium
High
Critical
Ubuntu Security Notice USN-8392-1
Topics Covered
Package Information
Get the latest News and Insights
Get the latest Linux and open source security news straight to your inbox.
Powered By
Linux Security - Your source for Top Linux News, Advisories, HOWTOs and Feature Releases
QUICK LINKS
subscribe to newsletters!
Like staying secure? So do we.
Sign up for updates, tips, and alerts!