The Linux kernel Landlock subsystem previously mis‑handled files and directories that were visible through a bind mount but had been moved or renamed out of scope of the mount point. When a sandboxed process accessed such a “disconnected” hierarchy, the kernel accumulated the subject’s access rights by walking the source filesystem tree without accounting for the missing mount point. This produced inconsistent and often wider permissions, allowing a sandboxed task that held limited write and read rights on the bind source and mount point to gain additional capabilities beyond what its Landlock policy had intended. The flaw is an access‑control weakness that can result in privilege escalation within the sandbox.

Any Linux system running a kernel that includes the Landlock file‑system security module is potentially impacted. The issue applies to all kernel configurations that enable Landlock; the fix is included in the current Linux kernel source via the specified commit. Installers must apply the patch or upgrade to a kernel release that incorporates the change to prevent the inconsistent permission handling.

The CVSS score of 8.8 signals a high severity vulnerability, while the EPSS score of less than 1 % indicates that exploitation is presently unlikely in the wild. The vulnerability is not listed in the CISA KEV catalog. The most probable attack path is a local sandboxed process that can create or modify a bind mount and perform a rename that crosses the mount boundary; by doing so it could obtain a broader set of file‑system permissions than its Landlock policy allows. Immediate patching of the kernel eliminates the risk, and for environments that cannot update immediately, reducing sandbox write access to bind‑mount sources or disabling the ability to create bind mounts can mitigate the exploit.