determine_backup_mode in src/uucore/src/lib/features/backup_control.rs only checks –backup/-b and returns BackupMode::None when only –suffix is given. GNU enables backup mode when –suffix is used alone (defaulting to existing/numbered, or $VERSION_CONTROL). Affects cp, install, mv, ln which share this code.
The safe_traversal module in uutils coreutils, which provides protection against Time-of-Check to Time-of-Use (TOCTOU) symlink races using file-descriptor-relative syscalls, is incorrectly limited to Linux targets. On other Unix-like systems such as macOS and FreeBSD, the utility fails to utilize these protections, leaving directory traversal operations vulnerable to symlink race conditions. Zellic finding 3.59. Reported in the Zellic uutils coreutils Program Security Assessment (for Canonical, Jan 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242.