RUSTSEC-2020-0142: Send bound needed on T (for Send impl of `Bucket2`)

What to do

1. See which version you have: cargo tree -i syncpool (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p syncpool. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example syncpool = "0.1.6") 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 implements Send for Bucket2. This allows sending non-Send types to other threads.

This can lead to data races when non Send types like Cell<T> or Rc<T> are contained inside Bucket2 and sent across thread boundaries. The data races can potentially lead to memory corruption (as demonstrated in the PoC from the original report issue).

The flaw was corrected in commit 15b2828 by adding a T: Send bound to the Send impl of Bucket2<T>.

References

• Package: crates.io/crates/syncpool
• Advisory: rustsec.org/advisories/RUSTSEC-2020-0142.html
• Report: github.com/Chopinsky/byte_buffer/issues/2

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