A native bridge is the code layer that connects JavaScript running inside a WebView to device capabilities exposed by the mobile app. It acts as a controlled interface between web content and native APIs such as camera access, storage, sensors, file operations, and other platform features. In hybrid apps, this bridge is a core part of the trust model, not just a convenience layer.
Security matters because any web content that reaches the bridge may inherit powerful app permissions. If an attacker can inject or redirect content into a trusted WebView, the bridge can become a path from hostile JavaScript to sensitive native functions. Defenders should treat bridge access as an authorization boundary: restrict which pages can load, validate URLs and origins carefully, minimize exposed methods, and avoid granting native access to untrusted or user-controlled content. In practice, many WebView attacks aim to cross this boundary and turn a browser-like view into a route to native code execution or data access.