Advisories for Npm/@Vitest/Browser package

Browser Mode exposes a set of built-in "commands" that run on the Node.js side of the test runner and can touch the local filesystem (taking screenshots, managing Playwright traces, uploading files for <input type="file">, comparing screenshots). Several of these commands accept a file path from the browser and act on it without checking the allowWrite permission gate and without confining the path to the project directory. A client that can …

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 …

Vitest browser mode served /vitest_test/ with the otelCarrier query parameter inserted directly into an inline module script. Because this value was treated as JavaScript source rather than data, an attacker could craft a browser-runner URL that executes arbitrary JavaScript in the Vitest server origin.

__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.