RUSTSEC-2026-0254: 
Rust vulnerability analysis and mitigation

Several methods in sp-sized-chunks drop elements before updating the container's 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 is later dropped, its own Drop re-visits those slots and drops the freed elements again — a use-after-free / double-free reachable from safe Rust. sp-sized-chunks is a fork of sized-chunks (companion advisory filed separately) and carries the same bug. The repository is archived and the crate is still on 0.1.0 with no fix available.

Impact

• CWE-415 (Double Free): the same allocation is freed twice (e.g. an element holding Box<T>).
• CWE-416 (Use-After-Free): an element reads its own freed allocation during Drop (e.g. String) — confirmed under AddressSanitizer. All are reachable from safe Rust via catch_unwind with element types whose Drop can panic.