rustsec-2026-0298

osv_rustsec
Description

`Storage::clear` walks the slab, empties each entry and frees the `Task` allocation once its reference count reaches zero. `self.tasks.set_len(0)` only runs after the loop. Emptying an entry drops the user future it holds, and `T` carries no bounds excluding a panicking `Drop`. If one unwinds, the length is never committed and `self.tasks` still holds the pointers already processed. `Drop for Storage` calls `clear` again, and the second pass dereferences `(*task.as_ptr()).entry` on allocations the first pass already freed — a use-after-free (CWE-416) reachable from safe Rust. `Storage` is reached only through `Unordered`, whose `Drop` calls `clear`. No particular method call is needed; dropping the container is enough. ## Mitigation Update to 0.10.3.

Timeline
Published
unknown
Last Modified
unknown
CVSS Details

CVSS details not available.

Affected Products

No product information available.

References
Linked Vulnerabilities

No linked vulnerabilities found.

{
  "affected": [
    {
      "database_specific": {
        "categories": [
          "memory-corruption"
        ],
        "cvss": null,
        "informational": null,
        "source": "https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0298.json"
      },
      "ecosystem_specific": {
        "affected_functions": null,
        "affects": {
          "arch": [],
          "functions": [
            "unicycle::Unordered::drop"
          ],
          "os": []
        }
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "unicycle",
        "purl": "pkg:cargo/unicycle"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-0"
            },
            {
              "fixed": "0.10.3"
            }
          ],
          "type": "SEMVER"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8gw6-724c-9h38"
  ],
  "database_specific": {
    "license": "CC0-1.0"
  },
  "details": "`Storage::clear` walks the slab, empties each entry and frees the `Task`\nallocation once its reference count reaches zero. `self.tasks.set_len(0)` only\nruns after the loop.\n\nEmptying an entry drops the user future it holds, and `T` carries no bounds\nexcluding a panicking `Drop`. If one unwinds, the length is never committed and\n`self.tasks` still holds the pointers already processed. `Drop for Storage`\ncalls `clear` again, and the second pass dereferences `(*task.as_ptr()).entry`\non allocations the first pass already freed — a use-after-free (CWE-416)\nreachable from safe Rust.\n\n`Storage` is reached only through `Unordered`, whose `Drop` calls `clear`. No\nparticular method call is needed; dropping the container is enough.\n\n## Mitigation\n\nUpdate to 0.10.3.",
  "id": "RUSTSEC-2026-0298",
  "modified": "2026-09-22T07:45:03.895643389Z",
  "published": "2026-09-12T12:00:00Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://crates.io/crates/unicycle"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0298.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com/udoprog/unicycle/commit/4f1492a266824f8aa66fd6b27fa6188bf826bdfd"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "Use-after-free when a future's `Drop` panics while the container is dropped"
}
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