VULNERABILITY INTELLIGENCE

CVE-2026-34983

CVSS score5 MEDIUM
EPSS probability0.12%
CISA KEVNot currently listed
Published2026-04-09
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

Description

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.

Weakness classification

  • security-advisories@github.com: CWE-416

Primary references