RUSTSEC-2026-0242: Safe ErrorRegistry APIs can cause undefined behavior

What to do

1. See which version you have: cargo tree -i dcrypt-api (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p dcrypt-api. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example dcrypt-api = "2.0.0") 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

All published versions of dcrypt-api before 2.0.0 exposed safe ErrorRegistry operations that could trigger undefined behavior when the default std feature was enabled.

Stored Box<E> values were erased to raw pointers and later deallocated as Box<()>. The get_error<E> operation also performed an unchecked cast to a caller-selected type. Finally, concurrent replacement or clearing could free a value while another thread cloned it. Ordinary safe Rust could therefore cause mismatched deallocation, type confusion, and use-after-free. Crates that re-exported this API are affected transitively.

Version 2.0.0 replaces the raw pointers with owned Box<dyn Any + Send> values behind a mutex, performs checked downcasts, and uses a mutation generation so concurrent stores and clears win safely. There is no reliable workaround while calling the affected registry API. Upgrade to 2.0.0 or later and avoid process-global error state where possible.

References

• Package: crates.io/crates/dcrypt-api
• Advisory: rustsec.org/advisories/RUSTSEC-2026-0242.html
• Web: github.com/ioi-foundation/dcrypt/commit/c99cc86f0ee353010cd202cbcd2c310371b0bbb8
• Web: github.com/ioi-foundation/dcrypt/commit/c99cc86f0ee353010cd202cbcd2c310371b0bbb8
• Web: github.com/ioi-foundation/dcrypt/releases/tag/v2.0.0

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