Is JavaScript-Java Bridge safe?

Low risk

JavaScript-Java Bridge relays messages between webpages and locally installed Java programs via native messaging, with no validation of which Java host a page may connect to.

The extension injects a content script into all pages and relays postMessage calls from page JavaScript to a local Java native host specified by the page itself. Because the programName field is passed to connectNative() without an allowlist check, any page loaded on a site the user has granted access to can direct the extension to connect to any registered native messaging host on the machine. The connected Java program can in turn read and write DOM properties and invoke JavaScript methods on the page.

Part of this rating comes from analysis signals we haven't published as detailed findings yet.

Advanced Machine Controlsv1.82Firefox Add-ons
17Risk

AI-generated. Findings may contain errors. Those marked Verified have been manually reviewed.

Publishers can request a review.

What it can do

Permissions this extension asks for, as declared in version 1.82. Asking for a permission is not a finding on its own - it is what the extension can do if it chooses to.

  • Talk to a program installed on your computer, outside the browser's sandbox

    nativeMessaging

  • Store data in your browser

    storage

Updated 21 September 2026amo-1475077