SB2026052281 - Cross-site scripting in vitest

Description

This security bulletin contains information about 1 vulnerability.

1) Cross-site scripting (CVE-ID: CVE-2026-47428)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to execute arbitrary JavaScript in the Vitest server origin.

The vulnerability exists due to cross-site scripting in the browser runner page at /__vitest_test__/ when processing the otelCarrier query parameter. A remote attacker can send a specially crafted browser-runner URL to execute arbitrary JavaScript in the Vitest server origin.

User interaction is required to open or navigate to a crafted browser-runner URL while the Vitest browser server is running. In the default local browser-mode setup, the resulting same-origin script execution can recover the embedded VITEST_API_TOKEN and be chained to authenticated API calls, including server-side code execution.

Remediation

Install update from vendor's website.

References

• https://github.com/vitest-dev/vitest/security/advisories/GHSA-2h32-95rg-cppp
• https://github.com/vitest-dev/vitest/blob/cba2036a197ec8ed42c35a37db78ef07192202c7/packages/browser/src/node/serverOrchestrator.ts#L48