---
id: RUSTSEC-2026-0254
title: >-
  Panic-safety unsoundness in `Chunk` and `InlineArray` (use-after-free /
  double-free)
summary: >-
  Panic-safety unsoundness in `Chunk` and `InlineArray` (use-after-free /
  double-free)
severity: none
vendor: sp-sized-chunks
product: sp-sized-chunks
ecosystem: rust
affected:
  - sp-sized-chunks >= 0.0.0-0
published: '2026-08-11'
updated: '2026-08-12'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/RUSTSEC-2026-0254'
references:
  - url: 'https://crates.io/crates/sp-sized-chunks'
  - url: 'https://rustsec.org/advisories/RUSTSEC-2026-0254.html'
tags:
  - osv
  - rust
ingestedAt: '2026-08-12T19:18:08.940Z'
---

## Overview

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.

## Affected packages

- `sp-sized-chunks >= 0.0.0-0`

## Remediation

Refer to the advisory for the patched release.