Out-of-bounds Write Affecting wasmtime package, versions >=28.0.0 <36.0.7>=37.0.0 <42.0.2>=43.0.0 <43.0.1
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-RUST-WASMTIME-15967235
- published10 Apr 2026
- disclosed9 Apr 2026
- creditShun Kashiwa
Introduced: 9 Apr 2026
NewCVE-2026-34987 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
Common Weakness Enumeration (CWE) is a category system for software weaknesses
How to fix?
Upgrade wasmtime to version 36.0.7, 42.0.2, 43.0.1 or higher.
Overview
Affected versions of this package are vulnerable to Out-of-bounds Write via incorrect memory offset handling in the Winch compiler backend. An attacker can execute arbitrary code, cause denial of service, or leak sensitive data by crafting a malicious WebAssembly module that accesses host memory outside its intended sandbox. This is only exploitable if the non-default Winch compiler backend is enabled.