SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-47428

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…

CRITICAL 9.6EPSS 0.61%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.6 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS
0.61% probability · 47th percentile
CISA KEV
Not listed
Weakness
CWE-79
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.