CVE-2025-64345

NameCVE-2025-64345
DescriptionWasmtime 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1120699

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
rust-wasmtime (PTS)trixie26.0.1+dfsg-3vulnerable
forky27.0.0+dfsg-3fixed
sid28.0.1+dfsg-3fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
rust-wasmtimesource(unstable)27.0.0+dfsg-21120699

Notes

[trixie] - rust-wasmtime <no-dsa> (Minor issue)
https://rustsec.org/advisories/RUSTSEC-2025-0118.html
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hc7m-r6v8-hg9q
Fixed by: https://github.com/bytecodealliance/wasmtime/commit/9ebb6934f00d58b92fb68ed0e0b16c0ae828ca10 (v38.0.4)

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