CVE-2025-64345

Publication date 13 November 2025

Last updated 13 November 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

1.8 · Low

Score breakdown

Description

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.

Status

Package Ubuntu Release Status
rust-wasmtime 25.10 questing
Needs evaluation
25.04 plucky
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy Not in release

Severity score breakdown

Parameter Value
Base score 1.8 · Low
Attack vector Local
Attack complexity High
Privileges required High
User interaction Required
Scope Unchanged
Confidentiality None
Integrity impact Low
Availability impact None
Vector CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:L/A:N

References

Other references