Arbitrary Code Injection Affecting @vitest/mocker package, versions >=2.1.0-beta.7 <4.1.12
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-JS-VITESTMOCKER-21347792
- published21 Oct 2026
- disclosed20 Oct 2026
- creditThai Son Dinh
Introduced: 20 Oct 2026
NewCVE-2026-112949 (opens in a new tab)How to fix?
Upgrade @vitest/mocker to version 4.1.12 or higher.
Overview
@vitest/mocker is a Vitest module mocker implementation
Affected versions of this package are vulnerable to Arbitrary Code Injection via the redirect mock handling in interceptorPlugin.ts and insufficient escaping in createManualModuleSource in utils.ts. In the redirect path, a URL pathname containing backslashes can escape the server root via path traversal, allowing an attacker to cause the server to serve files outside the intended root directory. In the manual mock source generation, module URLs and export names are interpolated directly into generated JavaScript without JSON serialization, allowing injection of arbitrary code into the generated module source.