CVE-2026-34983
Wasmtime is a runtime for WebAssembly. In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs. This bug is not controllable by guest Wasm programs. It can only be triggered by a specific sequence of embedder API calls made by the host. Specifically, the following steps must occur to trigger the bug clone a wasmtime::Linker, drop the original linker instance, use the new, cloned linker instance, resulting in a use-after-free. This vulnerability is fixed in 43.0.1.
- Score
- CVSS 3.1 5.0 Medium
- Status
- Analyzed - security-advisories@github.com
- Published
- 2026-04-09
- Last modified
- 2026-10-26
- Weaknesses
- CWE-416
Affected products
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2
