rustsec-2026-0255
Vulnerability from osv_rustsec
Published
2026-08-11 12:00
Modified
2026-08-12 10:22
Summary
Panic-safety unsoundness in `Chunk`, `RingBuffer`, and `InlineArray` (use-after-free / double-free)
Details

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.

Impact

  • CWE-415 (Double Free): the same allocation is freed twice.
  • CWE-416 (Use-After-Free): a freed allocation is accessed during a repeated Drop.

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

References
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "categories": [
          "memory-corruption"
        ],
        "cvss": null,
        "informational": "unsound"
      },
      "ecosystem_specific": {
        "affected_functions": null,
        "affects": {
          "arch": [],
          "functions": [
            "sized_chunks::Chunk::clear",
            "sized_chunks::Chunk::drop_left",
            "sized_chunks::Chunk::drop_right",
            "sized_chunks::InlineArray::clear",
            "sized_chunks::RingBuffer::clear",
            "sized_chunks::RingBuffer::drop_left",
            "sized_chunks::RingBuffer::drop_right"
          ],
          "os": []
        }
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "sized-chunks",
        "purl": "pkg:cargo/sized-chunks"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-0"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": []
    }
  ],
  "aliases": [],
  "database_specific": {
    "license": "CC0-1.0"
  },
  "details": "Several methods in `sized-chunks` drop elements before updating the length/boundary metadata. If an element\u0027s `Drop` panics during the drop, the metadata update is skipped, so the container still treats the already-dropped elements as live. When the container\u0027s own `Drop` runs, those elements are visited again \u2014 a use-after-free / double-free reachable from safe Rust.\n\nThe `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.\n\n## Impact\n\n- **CWE-415 (Double Free):** the same allocation is freed twice.\n- **CWE-416 (Use-After-Free):** a freed allocation is accessed during a repeated `Drop`.\n\nReachable entirely from safe Rust via `catch_unwind` with element types whose `Drop` can panic.",
  "id": "RUSTSEC-2026-0255",
  "modified": "2026-08-12T10:22:26Z",
  "published": "2026-08-11T12:00:00Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://crates.io/crates/sized-chunks"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0255.html"
    }
  ],
  "related": [],
  "severity": [],
  "summary": "Panic-safety unsoundness in `Chunk`, `RingBuffer`, and `InlineArray` (use-after-free / double-free)"
}



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