CVE-2026-53783 [HIGH] – rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnera

rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as –copy-unsafe-links, -D, and –log-file through rrsync to read or write files outside the permitted directory subtree.