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Ubuntu 22.04 Lowlatency High Socket Buffer Escalation USN-8388-2

ubuntu
Calendar Grey June 22, 2026
Dist Ubuntu Esm H88
Explore the security essentials of Ubuntu's new kernel update addressing privilege escalation issues with critical patches.
Several security issues were fixed in the Linux kernel.

Summary

Several security issues were fixed in the Linux kernel.

Software Description:

- linux-lowlatency: Linux low latency kernel

- linux-intel-iotg-5.15: Linux kernel for Intel IoT platforms

- linux-lowlatency-hwe-5.15: Linux low latency kernel

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. (CVE-2026-43284, CVE-2026-43500)

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,

CVE-2026-46300)

Qualys discovered that a race condition existed in the...

Read the Full Advisory

Topics%20covered

Topics Covered

security advisory privilege escalation Ubuntu kernel high socket buffer

Update Instructions

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

Ubuntu 22.04 LTS
   linux-image-5.15.0-181-lowlatency  5.15.0-181.191
   linux-image-5.15.0-181-lowlatency-64k  5.15.0-181.191
   linux-image-lowlatency          5.15.0.181.152
   linux-image-lowlatency-5.15     5.15.0.181.152
   linux-image-lowlatency-64k      5.15.0.181.152
   linux-image-lowlatency-64k-5.15  5.15.0.181.152

Ubuntu 20.04 LTS
   linux-image-5.15.0-1104-intel-iotg  5.15.0-1104.110~20.04.1
                                   Available with Ubuntu Pro
   linux-image-5.15.0-181-lowlatency  5.15.0-181.191~20.04.1
                                   Available with Ubuntu Pro
   linux-image-5.15.0-181-lowlatency-64k  5.15.0-181.191~20.04.1
                                   Available with Ubuntu Pro
   linux-image-intel               5.15.0.1104.110~20.04.1
                                   Available with Ubuntu Pro
   linux-image-intel-iotg          5.15.0.1104.110~20.04.1
                                   Available with Ubuntu Pro
   linux-image-intel-iotg-5.15     5.15.0.1104.110~20.04.1
                                   Available with Ubuntu Pro
   linux-image-lowlatency-5.15     5.15.0.181.191~20.04.1
                                   Available with Ubuntu Pro
   linux-image-lowlatency-64k-5.15  5.15.0.181.191~20.04.1
                                   Available with Ubuntu Pro
   linux-image-lowlatency-64k-hwe-20.04  5.15.0.181.191~20.04.1
                                   Available with Ubuntu Pro
   linux-image-lowlatency-hwe-20.04  5.15.0.181.191~20.04.1
                                   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-8388-2

https://ubuntu.com/security/notices/USN-8388-1

CVE-2026-43284, CVE-2026-43494, CVE-2026-43500, CVE-2026-43503,

CVE-2026-46300, CVE-2026-46333

Severity
high
Lowest
Low
Medium
High
Critical

Ubuntu Security Notice USN-8388-2

Topics%20covered

Topics Covered

security advisory privilege escalation Ubuntu kernel high socket buffer

Package Information

https://launchpad.net/ubuntu/+source/linux-lowlatency/5.15.0-181.191

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