Wasmtime provides unsound API access to a WebAssembly shared linear memory
Summary
Wasmtime provides unsound API access to a WebAssembly shared linear memory
Original description
The description as published by the source.
Wasmtime is a runtime for WebAssembly. Prior to version 38.0.4, 37.0.3, 36.0.3, and 24.0.5, Wasmtime's Rust embedder API contains an unsound interaction where a WebAssembly shared linear memory could be viewed as a type which provides safe access to the host (Rust) to the contents of the linear memory. This is not sound for shared linear memories, which could be modified in parallel, and this could lead to a data race in the host. Patch releases have been issued for all supported versions of Wasmtime, notably: 24.0.5, 36.0.3, 37.0.3, and 38.0.4. These releases reject creation of shared memories via Memory::new and shared memories are now excluded from core dumps. As a workaround, eembeddings affected by this issue should use SharedMemory::new instead of Memory::new to create shared memories. Affected embeddings should also disable core dumps if they are unable to upgrade. Note that core dumps are disabled by default but the wasm threads proposal (and shared memory) is enabled by default.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2025-64345 rust-wasmtime
- Ubuntu UBUNTU-CVE-2025-64345 rust-wasmtime
References
- advisory rustsec.org
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package crates.io
- patch github.com
- web docs.rs
- web docs.rs
- web docs.wasmtime.dev
- web github.com