RUSTSEC-2020-0117: QueueSender<T>/QueueReceiver<T>: Send/Sync impls need `T: Send`

What to do

1. See which version you have: cargo tree -i conqueue (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p conqueue. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example conqueue = "0.4.0") or update the dependency that pulls it in.
3. Check again with cargo audit, or paste your Cargo.lock into our Cargo.toml checker.

Details from the advisory

Affected versions of this crate unconditionally implemented Send/Sync for QueueSender<T>, allowing to send non-Send T to other threads by invoking (&QueueSender<T>).send().

This fails to prevent users from creating data races by sending types like Rc<T> or Arc<Cell<T>> to other threads, which can lead to memory corruption.

The flaw was corrected in commit 1e462c3 by imposing T: Send to both Send/Sync impls for QueueSender<T>/QueueReceiver<T>.

References

• Package: crates.io/crates/conqueue
• Advisory: rustsec.org/advisories/RUSTSEC-2020-0117.html
• Report: github.com/longshorej/conqueue/issues/9

From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.