Description
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.
References8
- github.com/vitest-dev/vitest/commit/18af98cee1830604d57f6a02bf2…
- github.com/vitest-dev/vitest/commit/3514f9fa135c90e1c35754fc4d2…
- github.com/vitest-dev/vitest/pull/10283
- github.com/vitest-dev/vitest/pull/10285
- github.com/vitest-dev/vitest/releases/tag/v4.1.6
- github.com/vitest-dev/vitest/releases/tag/v5.0.0-beta.3
- github.com/vitest-dev/vitest/security/advisories/GHSA-2h32-95rg…
- github.com/vitest-dev/vitest/security/advisories/GHSA-2h32-95rg…
Metrics
- CVSS 3.1
-
9.6
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 48 · as of 15 November 2026
- CWE
- CWE-79
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.