WebUSB is a browser API that lets web pages communicate with compatible USB devices after the user grants permission. It can let a device work through a browser instead of requiring a separate companion app. The browser’s permission controls help limit access, but the page, browser session, and connected device all become part of the trusted path.
In security, WebUSB matters because browser-based hardware access can expose sensitive functions if users approve access on an untrusted or misleading page. In real deployments, a page may use it to configure or operate a peripheral; attackers could try to exploit weak page integrity, deceptive permission requests, or unclear device behavior. Defenses include keeping browsers and device firmware updated, verifying the site before granting access, and requesting access only to the intended device. WebUSB is not inherently unsafe, but its permissions and trust boundaries should be treated as security-sensitive.