Advisories for Npm/@Vitest/Browser package

2026

Vitest Browser: Exposed Browser Mode API Can Proxy CDP and Overwrite Config Files, Leading to RCE

Vitest Browser Mode exposes a cdp() API that forwards raw Chrome DevTools Protocol (CDP) methods over the Vitest browser WebSocket RPC. CDP is not gated by browser.api.allowWrite, browser.api.allowExec, api.allowWrite, or api.allowExec. As a result, disabling Browser Mode write and exec operations does not prevent a browser API client from using CDP to perform equivalent actions. In a verified reproduction with allowWrite: false and allowExec: false, CDP Page.setDownloadBehavior set the browser …

2025

Vitest browser mode serves arbitrary files

__screenshot-error handler on the browser mode HTTP server that responds any file on the file system. Especially if the server is exposed on the network by browser.api.host: true, an attacker can send a request to that handler from remote to get the content of arbitrary files.