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

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.