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Ubuntu 20.04 8391-1 Linux Kernel Critical Escalation Issues

ubuntu
Calendar Grey June 4, 2026
Dist Ubuntu Esm H88
========================================================================== Ubuntu Security Notice US
Several security issues were fixed in the Linux kernel.

Summary

Several security issues were fixed in the Linux kernel.

Software Description:

- linux-raspi: Linux kernel for Raspberry Pi systems

- linux-raspi-5.4: Linux kernel for Raspberry Pi systems

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.

This update cor...

Read the Full Advisory

Topics%20covered

Topics Covered

security advisory critical privilege escalation Ubuntu network vulnerability linux-raspi

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS
   linux-image-5.4.0-1143-raspi    5.4.0-1143.156
                                   Available with Ubuntu Pro
   linux-image-raspi               5.4.0.1143.174
                                   Available with Ubuntu Pro
   linux-image-raspi-5.4           5.4.0.1143.174
                                   Available with Ubuntu Pro
   linux-image-raspi2              5.4.0.1143.174
                                   Available with Ubuntu Pro

Ubuntu 18.04 LTS
   linux-image-5.4.0-1143-raspi    5.4.0-1143.156~18.04.1
                                   Available with Ubuntu Pro
   linux-image-raspi-5.4           5.4.0.1143.156~18.04.1
                                   Available with Ubuntu Pro
   linux-image-raspi-hwe-18.04     5.4.0.1143.156~18.04.1
                                   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-8391-1

CVE-2024-50304, CVE-2026-23112, CVE-2026-23209, 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

Severity
critical
Lowest
Low
Medium
High
Critical

Ubuntu Security Notice USN-8391-1

Topics%20covered

Topics Covered

security advisory critical privilege escalation Ubuntu network vulnerability linux-raspi

Package Information

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