CVE-2026-34983

Fixed in a distro release EPSS <1%CVSS 1.0

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.

Published 2026-04-09 · CVE record · OSV

Products: bytecodealliance wasmtime

Fixed upstream

Distro releases