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Ubuntu 18.04 LTS Linux Kernel Security Update USN-8819-3 CVE-2025

Ubuntu 18.04 LTS Linux Kernel Security Update USN-8819-3 CVE-2025

Linuxsecurity •LinuxSecurity Advisories • September 29, 2026

CISA confirms exploitation of a Linux firewall flaw. Check if your systems need the fix. ×

Several security issues were fixed in the Linux kernel. Software Description: - linux-azure-4.15: Linux kernel for Microsoft Azure Cloud systems - linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems - linux-azure: Linux kernel for Microsoft Azure Cloud systems Details: 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: - Network file system (NFS) server daemon; - IPv6 networking; - Netfilter; (CVE-2025-38724, CVE-2026-53131, CVE-2026-53221)

Several security issues were fixed in the Linux kernel.

Software Description:

- linux-azure-4.15: Linux kernel for Microsoft Azure Cloud systems

- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems

- linux-azure: Linux kernel for Microsoft Azure Cloud systems

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:

- Network file system (NFS) server daemon;

(CVE-2025-38724, CVE-2026-53131, CVE-2026-53221)

The problem can be corrected by updating your system to the following package versions: Ubuntu 18.04 LTS linux-image-4.15.0-1207-azure 4.15.0-1207.222 Available with Ubuntu Pro linux-image-azure-4.15 4.15.0.1207.175 Available with Ubuntu Pro linux-image-azure-lts-18.04 4.15.0.1207.175 Available with Ubuntu Pro Ubuntu 16.04 LTS linux-image-4.15.0-1197-aws 4.15.0-1197.210~16.04.1 Available with Ubuntu Pro linux-image-aws-hwe 4.15.0.1197.210~16.04.1 Available with Ubuntu Pro Ubuntu 14.04 LTS linux-image-4.15.0-1207-azure 4.15.0-1207.222~14.04.1 Available with Ubuntu Pro linux-image-azure 4.15.0.1207.222~14.04.1 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.

CVE-2025-38724, CVE-2026-53131, CVE-2026-53221

Ubuntu Security Notice USN-8819-3

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