CVE-2026-53361: AF_UNIX GC vs MSG_PEEK Use-After-Free Container Escape

CVE-2026-53361 AF_Unix GC vs. MSG_PEEK use-after-free container escape

This repository presents a proof-of-concept exploit for CVE-2026-53361, a use-after-free vulnerability in the AF_UNIX socket garbage collector that allows unprivileged container escape. The bug arises from a race condition where a concurrent MSG_PEEK on an in-flight socket can bypass the garbage collector's census, leading to a dangling sk_buff. The exploit targets several kernels, including stable 6.12, Ubuntu 24.04 HWE, and RHEL 10, and notes that the 7.x kernels and Ubuntu 6.8 GA are vulnerable but out of scope. The author mentions that the exploit is designed for systems with fewer than 8 CPUs and that cache armoring is stripped for simplicity.