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CVE PROGRAM SOURCE RECORD1.0 Low

CVE-2026-34983

Wasmtime has a use-after-free bug after cloning `wasmtime::Linker`

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

bytecodealliance wasmtime

  • >= 43.0.0, < 43.0.1affected

References