Several methods in sized-chunks drop elements before updating the length/boundary metadata. If an element's Drop panics during the drop, the metadata update is skipped, so the container still treats the already-dropped elements as live. When the container's own Drop runs, those elements are visited again — a use-after-free / double-free reachable from safe Rust.

The RingBuffer methods require the ringbuffer feature. This is distinct from RUSTSEC-2020-0041 (Chunk::clone / insert from, fixed in 0.6.3); the methods here are still affected in 0.7.0. The repository is archived with issues/PRs disabled and no fix available.

Reachable entirely from safe Rust via catch unwind with element types whose Drop can panic.