Use After Free Affecting rust-wasmtime package, versions <36.0.7+dfsg-1


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.12% (2nd percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-RUSTWASMTIME-15996444
  • published12 Apr 2026
  • disclosed9 Apr 2026

Introduced: 9 Apr 2026

CVE-2026-34983  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Debian:unstable rust-wasmtime to version 36.0.7+dfsg-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rust-wasmtime package and not the rust-wasmtime package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1