RUSTSEC-2020-0151: Generators can cause data races if non-Send types are used in their generator functions

What to do

1. See which version you have: cargo tree -i generator (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p generator. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example generator = "0.7.0") 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

The Generator type is an iterable which uses a generator function that yields values. In affected versions of the crate, the provided function yielding values had no Send bounds despite the Generator itself implementing Send.

The generator function lacking a Send bound means that types that are dangerous to send across threads such as Rc could be sent as part of a generator, potentially leading to data races.

This flaw was fixed in commit f7d120a3b by enforcing that the generator function be bound by Send.

References

• Package: crates.io/crates/generator
• Advisory: rustsec.org/advisories/RUSTSEC-2020-0151.html
• Report: github.com/Xudong-Huang/generator-rs/issues/27

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

Other advisories for generator

• Vulnerability HighRUSTSEC-2019-0020 · 2019-09-06fix unsound APIs that could lead to UB

Full security history of generator