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 b…

Vulnerability class: XSS (Cross-Site Scripting)

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

Weakness classification (CWE)

References

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.