RUSTSEC-2026-0292 Double free / use-after-free in `Chunk` and `InlineArray` removal methods when an element's `Drop` panics
A double free or use-after-free vulnerability in Rust collection libraries allows attackers to cause crashes or potentially execute code if element drop panics.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- Available
What is RUSTSEC-2026-0292?
RUSTSEC-2026-0292 is an use after free vulnerability in imbl-sized-chunks, published on 4 Sep 2026.
Official description
Chunk::{clear, drop_left, drop_right} and InlineArray::{clear, truncate} drop the removed elements before updating the metadata that records which slots hold live values — the left/right index pair for Chunk, the length field for InlineArray. If an element's Drop panics during the drop, that update is never reached, so the collection still treats the already-dropped elements as live. When the collection is later dropped (its destructor walks the range described by the stale metadata), or a subsequent operation touches the same slots, those elements are dropped a second time — a double free (CWE-415) / use-after-free (CWE-416) reachable from safe Rust.
The stale field is left and right for Chunk::clear, left for drop_left, right for drop_right, and the length field for both InlineArray methods.
Mitigation
Upgrade to imbl-sized-chunks 0.2.0 or later, which commits the metadata before dropping any element (fixed in jneem/imbl-sized-chunks#14, released in 0.2.0).
Which versions are affected by RUSTSEC-2026-0292?
1 open source package ship an affected version, including imbl-sized-chunks.
| Package | Affected | Fixed in |
|---|---|---|
imbl-sized-chunks crates.io | From 0.0.0-0 | 0.2.0 |
How do I fix RUSTSEC-2026-0292?
Upgrade imbl-sized-chunks to 0.2.0 or later.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is RUSTSEC-2026-0292 being exploited?
There is no known exploitation of RUSTSEC-2026-0292 in the wild and no public exploit code.