RCE in @Vitest Mocker
CVE-2026-112949
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.
Vulnerability class: RCE (Remote Code Execution)
Published .
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- @Vitest Mocker — versions >= 2.1.0-beta.7, < 4.1.12, >= 5.0.0, < 5.0.3
- Vitest-Dev Vitest — versions >= 2.1.0-beta.7, < 4.1.12, >= 5.0.0, < 5.0.3
Weakness classification (CWE)
References
- github.com/vitest-dev/vitest/security/advisories/GHSA-qxg6-89mg-rqv8
- github.com/vitest-dev/vitest/commit/15cc006aa9f8683dc5f7e895d011fa7dc751ce35
- github.com/vitest-dev/vitest/commit/b825313243dc55757e8d7c0f9e7a792135e13473
- github.com/vitest-dev/vitest/releases/tag/v4.1.12
- github.com/vitest-dev/vitest/releases/tag/v5.0.3
Frequently asked questions
- What is CVE-2026-112949?
- CVE-2026-112949 is a medium-severity vulnerability in @Vitest Mocker, classified under Code Injection. CVSS score: 4.7/10. Published 2026-10-20.
- How severe is CVE-2026-112949?
- Medium severity. CVSS v3 base score is 4.7 out of 10.