CVE-2026-72183

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A bypass exists in the Landlock security module regarding the LANDLOCK SCOPE SIGNAL restriction, which is intended to prevent sandboxed processes from signaling processes outside their Landlock domain. This bypass occurs through the asynchronous SIGIO delivery path. A sandboxed process owning a file or socket can use fcntl() with F SETOWN, F SETSIG, and O ASYNC to trigger the kernel to deliver signals to an entire process group. If the group includes a non-sandboxed process, such as a supervisor or security monitor, the sandbox can signal or kill it.

The issue stems from control current fowner() skipping the recording of the Landlock domain when the target is in the caller's thread group, which is only safe for single-task targets. Consequently, hook file send sigiotask() allows signals to fan out to the whole group unchecked. The fix involves recording the domain for every non single-process target and recording the registrant's thread group to ensure same-process delivery is allowed while blocking out-of-domain members.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.