RUSTSEC-2026-0254: Panic-safety unsoundness in `Chunk` and `InlineArray` (use-after-free / double-free)

What to do

1. Find who pulls it in: cargo tree -i sp-sized-chunks.
2. Avoid the affected API (sp_sized_chunks::Chunk::clear, sp_sized_chunks::Chunk::drop_left, sp_sized_chunks::Chunk::drop_right, sp_sized_chunks::InlineArray::clear), or replace the crate.

Details from the advisory

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.

References

• Package: crates.io/crates/sp-sized-chunks
• Advisory: rustsec.org/advisories/RUSTSEC-2026-0254.html

From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.

Other advisories for sp-sized-chunks

• UnmaintainedRUSTSEC-2026-0270 · 2026-08-11`sp-sized-chunks` is unmaintained

Full security history of sp-sized-chunks