Home / mailings

PDF

[USN-8818-2] Linux kernel (IBM) vulnerabilities

Posted on 25 September 2026
Ubuntu Security

==========================================================================Ubuntu Security Notice USN-8818-2
September 25, 2026

linux-ibm-5.15 vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-ibm-5.15: Linux kernel for IBM cloud systems

Details:

It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)

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:
- ARM64 architecture;
- InfiniBand drivers;
- Network drivers;
- TCM subsystem;
- exFAT file system;
- Network file system (NFS) client;
- Network file system (NFS) server daemon;
- B.A.T.M.A.N. meshing protocol;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- RDS protocol;
(CVE-2026-53186, CVE-2026-53216, CVE-2026-53221, CVE-2026-53354,
CVE-2026-53355, CVE-2026-53398, CVE-2026-63800, CVE-2026-63808,
CVE-2026-63887, CVE-2026-63888, CVE-2026-63912, CVE-2026-63922,
CVE-2026-63924, CVE-2026-63984, CVE-2026-63992, CVE-2026-63993,
CVE-2026-63994, CVE-2026-64007, CVE-2026-64091)

Update instructions:

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

Ubuntu 20.04 LTS
linux-image-5.15.0-1110-ibm 5.15.0-1110.114~20.04.1
Available with Ubuntu Pro
linux-image-ibm 5.15.0.1110.114~20.04.1
Available with Ubuntu Pro
linux-image-ibm-5.15 5.15.0.1110.114~20.04.1
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-8818-2
https://ubuntu.com/security/notices/USN-8818-1
CVE-2025-10263, CVE-2026-53186, CVE-2026-53216, CVE-2026-53221,
CVE-2026-53354, CVE-2026-53355, CVE-2026-53398, CVE-2026-63800,
CVE-2026-63808, CVE-2026-63887, CVE-2026-63888, CVE-2026-63912,
CVE-2026-63922, CVE-2026-63924, CVE-2026-63984, CVE-2026-63992,
CVE-2026-63993, CVE-2026-63994, CVE-2026-64007, CVE-2026-64091

--===============4709858740370214154==Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature

 

TOP