Exploit Released for Unpatched Ubuntu Linux Flaw Enabling Host-Root Container Escape

Exploit Released for Unpatched Ubuntu Linux Flaw Enabling Host-Root Container Escape Swati KhandelwalSep 23, 2026Vulnerability / Linux A use-after-free in the Linux kernel's AF_UNIX socket subsystem can be used to escape a container and gain root on the host, security firm DepthFirst said in research published September 22. The flaw, tracked as CVE-2026-80521 (CVSS score: 7.8), was fixed upstream on August 6, but Ubuntu has not shipped the patch for its 26.04, 24.04, or 22.04 LTS releases. DepthFirst released exploit code targeting Ubuntu 26.04. Ubuntu's security tracker lists the Linux package on 26.04 as "vulnerable, work in progress." The 24.04 and 22.04 releases are also affected through newer kernel packages, including those for AWS, Azure, and GCP workloads. No fix…