XSS in Vitest-Dev Vitest
CVE-2026-47428
Vitest is a testing framework powered by Vite. From 4.0.17 until 4.1.6 and 5.0.0-beta.3, Vitest Browser Mode served /__vitest_test__/ with the otelCarrier query parameter inserted directly into an inline module script, allowing a crafted browser-runner URL to execute arbitrary JavaScript in the Vitest server origin and recover VITEST_API_TOKEN for authenticated API calls. This issue is fixed in versions 4.1.6 and 5.0.0-beta.3.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.006 (46.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.
Affected products
- Vitest-dev Vitest — versions >= 4.0.17, < 4.1.6, >= 5.0.0-beta.0, < 5.0.0-beta.3
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-47428?
- CVE-2026-47428 is a critical-severity vulnerability in Vitest-Dev Vitest, classified under Cross-site Scripting. CVSS score: 9.6/10. Published 2026-07-14.
- How severe is CVE-2026-47428?
- Critical severity. CVSS v3 base score is 9.6 out of 10.