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[ CVE-2026-112949 · Published 20 Oct 2026 ]

Vitest: Code injection via unauthenticated manual mock registration

CVSS 4.7 EPSS <1%Fix available

[ Description ]Official description

Vitest is a Vite-native testing framework for JavaScript and TypeScript projects. From 2.1.0-beta.7 until 4.1.12 and 5.0.3, an unauthenticated non-browser WebSocket client that can reach a development server using interceptorPlugin can register a manual mock whose attacker-controlled url createManualModuleSource inserts unescaped into generated module source. When the developer browser loads the affected module, attacker-controlled JavaScript executes on the development-server origin. This issue is fixed in versions 4.1.12 and 5.0.3.

[ Fixes ]Fixes and patches

  • @vitest/mocker 4.1.12Fixed version · GitHub Advisories · npm package @vitest/mocker: upgrade to 4.1.12 or later (affected >= 2.1.0-beta.7, < 4.1.12)
  • @vitest/mocker 5.0.3Fixed version · GitHub Advisories · npm package @vitest/mocker: upgrade to 5.0.3 or later (affected >= 5.0.0-beta.1, < 5.0.3)

[ Packages ]Affected open-source packages

[ References ]References