GHSA-4c7q-4928-8445: chmod: --preserve-root bypassed by any path that resolves to root (e.g. /../)

Chmoder::chmod() only compares the literal argument against Path::new("/"), so the --preserve-root guard is bypassed by any path that *resolves* to root — a symlink to / or simply /../. if self.recursive && self.preserve_root && file == Path::new("/") { return Err(ChmodError::PreserveRoot("/".to_string()).into()); } PoC — recursively chmods the entire filesystem to 000 despite --preserve-root: chmod -R --preserve-root 000 /../ -v Impact: --preserve-root is the documented safeguard against destructive recursive operations on /. Bypassing it allows chmod -R to alter permissions across the whole filesystem, causing a complete system breakdown. Recommendation: canonicalize the target path before comparing against root. Remediation: Acknowledged by Canonical; fixed in commit 413055b3. _Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242. Finding 3.1. Credit: Zellic._