Ubuntu alert USN-8388-2 (linux-intel-iotg-5.15, linux-lowlatency, linux-lowlatency-hwe-5.15)

From:
             
 
Rodrigo Figueiredo Zaiden via ubuntu-security-announce <ubuntu-security-announce@lists.ubuntu.com>
To:
             
 
ubuntu-security-announce@lists.ubuntu.com
Subject:
             
 
[USN-8388-2] Linux kernel vulnerabilities
Date:
             
 
Mon, 22 Jun 2026 20:03:51 -0300
Message-ID:
             
 
<346df604-b923-458e-a6c1-2aaaf23a42bd@canonical.com>
Cc:
             
 
Rodrigo Figueiredo Zaiden <rodrigo.zaiden@canonical.com>
==========================================================================
Ubuntu Security Notice USN-8388-2
June 22, 2026

linux-intel-iotg-5.15, linux-lowlatency, linux-lowlatency-hwe-5.15
vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

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 ptrace subsystem of
the Linux kernel when privileged processes are exiting. An unprivileged
local attacker could use this issue to expose sensitive information.
(CVE-2026-46333)

Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
   - RDS protocol;
(CVE-2026-43494)

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

Package Information:
   https://launchpad.net/ubuntu/+source/linux-lowlatency/5.1...



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