CVE-2026-34983Published

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

Exact source revision recorded 23 Oct 2026 15:48:27 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2026-34983

Published

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.

Source published: 9 Apr 2026 18:47:26 UTC
Source modified: 13 Apr 2026 15:38:33 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 4.0 · 1.0 CVSS:4.0/AV:P/AC:H/AT:P/PR:H/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N