Linux Kernel Container Escape Vulnerability (CVE-2026-80521)
Posted on
September 25, 2026
Information Security Advisory
A recently disclosed vulnerability (CVE-2026-80521) affects the Linux kernel AF_UNIX socket subsystem and may allow an attacker to escape a container and obtain root privileges on the host system. Severity level: CVSS Score: 7.8/High Description: CVE-2026-80521 is a use-after-free vulnerability in the Linux kernel's AF_UNIX socket subsystem caused by a race condition in the garbage collection mechanism used to manage file descriptors passed through SCM_RIGHTS messages. An attacker with code execution inside a container can exploit the flaw to corrupt kernel memory, escape container isolation, and gain root privileges on the underlying host. Affected Versions:
Ubuntu 26.04 LTS
Ubuntu 24.04 LTS
Ubuntu 22.04 LTS
Red Hat Enterprise Linux 10
Debian 12,13,14
Upstream Linux Kernel (All versions prior to official patch committed on Aug 6, 2026)
Impact: Successful exploitation may allow attackers to obtain root privileges on the host operating system. Resolution: Apply vendor-provided kernel updates as soon as they become available. Monitor Ubuntu and vendor security advisories for package availability. Reference:
