Security Advisory Desk
unratedQCS priority 70/100Ubuntu

USN-8725-1: Linux kernel vulnerabilities

Multiple security vulnerabilities were found in the Linux kernel used by Ubuntu. These flaws affect various system parts, such as drivers for NVIDIA Tegra hardware, different file systems, networking protocols, and firewall components. Attackers might exploit these weaknesses to take control of or disrupt affected systems. Ubuntu has released updates to address these problems, and users should install them and restart their machines to protect their systems.

Published 4/9/2026, 5:51:55 pmVerified 6/9/2026, 12:07:03 pmRevision 1
Ubuntu unrated network security advisory visual

In plain language

What this advisory means

Multiple security vulnerabilities were found in the Linux kernel used by Ubuntu. These flaws affect various system parts, such as drivers for NVIDIA Tegra hardware, different file systems, networking protocols, and firewall components. Attackers might exploit these weaknesses to take control of or disrupt affected systems. Ubuntu has released updates to address these problems, and users should install them and restart their machines to protect their systems.

Technical explanation

How the issue affects the environment

Several vulnerabilities were identified in key Linux kernel components including the NVIDIA Tegra memory controller driver, file systems infrastructure, NFS server daemon, OCFS2 file system, B.A.T.M.A.N. meshing protocol, Netfilter firewall framework, and the SCTP transport protocol. These flaws potentially allow attackers to compromise system integrity or availability. The kernel fixes increment the ABI version, requiring recompilation and reinstallation of third-party kernel modules after upgrading. Updates are available for Ubuntu 14.04 LTS and 16.04 LTS variants, including FIPS-certified kernels and cloud or virtualization-specific kernels.

Operational impact

Why teams should care

If left unpatched, attackers could exploit these kernel vulnerabilities to gain unauthorized system control, disrupt services, or undermine data integrity across Ubuntu systems. This risk affects a broad range of deployments, from desktop systems to servers and cloud instances, potentially impacting confidentiality, availability, and compliance requirements.

Immediate action

Apply the available Ubuntu security updates for the Linux kernel packages promptly. After updating, reboot the computer to activate the new kernel versions. Also, recompile and reinstall all third-party kernel modules due to ABI changes introduced by this update.

Affected and fixed releases

Affected versionsUbuntu 14.04 LTS, Ubuntu 16.04 LTS
Fixed versionsUbuntu 14.04 LTS updated linux-image packages (e.g., 4.4.0-287), Ubuntu 16.04 LTS updated linux-image packages (e.g., 4.4.0-1128, 4.4.0-1159)

Temporary risk reduction

The official source does not specify any workaround. The issue should be addressed by applying the updates provided by Ubuntu and rebooting.

Evidence and validation checklist

  • Ubuntu security notice USN-8725-1 published on 2026-09-04
  • Description of affected kernel subsystems and associated CVEs
  • Instructions for updating kernel packages and rebooting
  • Mention of ABI change requiring recompilation of third-party modules

Authoritative reference

Ubuntu Security Notices

QCS detected and normalized this record from the official source. Vendor guidance remains authoritative.

Open source
USN-8725-1: Linux kernel vulnerabilities | Advisory | QCS