Vulnerability HighRUSTSEC-2020-0091 · arc-swap
RUSTSEC-2020-0091: Dangling reference in `access::Map` with Constant
Short answerA security vulnerability in the arc-swap crate: Dangling reference in `access::Map` with Constant. High severity (CVSS 7.5). Fixed in 0.4.8, 1.1.0: update to a fixed version.
| Crate | arc-swap |
|---|---|
| Type | Vulnerability (memory-corruption) |
| Affected versions | From 0.4.2 before 0.4.8; from 1.0.0 before 1.1.0. |
| Fixed in | 0.4.8, 1.1.0 |
| Severity | High, CVSS 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Published | 2020-12-10 |
| Last changed | 2023-11-08 |
| Also known as | CVE-2020-35711, GHSA-9pqx-g3jh-qpqq |
| Affected functions | arc_swap::access::MapGuard::deref |
What to do
- See which version you have:
cargo tree -i arc-swap(it also shows which of your dependencies pulls it in). - Update within your version requirement:
cargo update -p arc-swap. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for examplearc-swap = "1.1.0") or update the dependency that pulls it in. - Check again with
cargo audit, or paste your Cargo.lock into our Cargo.toml checker.
Details from the advisory
Using the arc_swap::access::Map with the Constant test helper (or with user-provided implementation of the Access trait) could sometimes lead to the map returning dangling references.
Replaced by implementation without unsafe, at the cost of added Clone bound on the closure and small penalty on performance.
References
- Package: crates.io/crates/arc-swap
- Advisory: rustsec.org/advisories/RUSTSEC-2020-0091.html
- Report: github.com/vorner/arc-swap/issues/45
From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.
Up next
Same cratearc-swap: security historyEvery advisory for this crate, and whether it is safe to use today.Read it next →Did this answer your question?