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.
References6
- github.com/vitest-dev/vitest/commit/15cc006aa9f8683dc5f7e895d01…
- github.com/vitest-dev/vitest/commit/b825313243dc55757e8d7c0f9e7…
- github.com/vitest-dev/vitest/releases/tag/v4.1.12
- github.com/vitest-dev/vitest/releases/tag/v5.0.3
- github.com/vitest-dev/vitest/security/advisories/GHSA-qxg6-89mg…
- github.com/vitest-dev/vitest/security/advisories/GHSA-qxg6-89mg…
Metrics
- CVSS 3.1
-
4.7
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 27 · as of 9 November 2026
- CWE
- CWE-94CWE-116CWE-306
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.