1.0
Low
CVE-2026-34983 Wasmtime is a runtime for WebAssembly
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 and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| wasmtime 43.0 | 43.0.0 → < 43.0.1 | 43.0.1 |
Other CVEs of wasmtime
The 81 CVEs of wasmtime →
CVE-2026-121441
Wasmtime before 36.0.19, 37.0.0 before 48.0.7, and 49.0.0 before 49.0.4 contains a request smuggling vulnerability in…
6.3
Medium
CVE-2026-121440
Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 fails to check forwarded trailers against the…
6.3
Medium
CVE-2026-121439
Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 contains a response splitting vulnerability in wasi-http p3…
6.9
Medium
CVE-2026-119143
Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Panic via Zero-Length Stream Writes
5.9
Medium