Advisories for Cargo/Wasmtime-C-Api-Impl package

2026

Wasmtime: Memory leak in C API with `externref` and `anyref` types

Wasmtime 37.0.0 and 37.0.1 have memory leaks in the C/C++ API when using bindings for the anyref or externref WebAssembly values. This is caused by a regression introduced during the development of 37.0.0 and all prior versions of Wasmtime are unaffected. If anyref or externref is not used in the C/C++ API then embeddings are also unaffected by the leaky behavior. The wasmtime Rust crate is unaffected by this leak. …