Researchers have demonstrated how a single browser extension can take control of the AI assistant built into Chrome, Edge, Comet, Opera Neon, and the Claude extension in Chrome, causing it to act on your behalf.
More and more browsers have a built-in AI assistant—Gemini in Chrome, Copilot in Edge, Perplexity Comet—that can view the page, open files, and take action on your behalf. Researchers at Forever Security demonstrated, in a study called BragJack, that a single ordinary browser extension can take control of this assistant in five products: Chrome (Gemini), Microsoft Edge, Perplexity Comet, Opera Neon, and the Claude extension in Chrome.
The idea behind the attack is simple. The AI assistant only accepts commands from a trusted page belonging to the manufacturer. The extension, using two common permissions (the same ones required by ad blockers), infiltrates that page and issues commands as if it were the manufacturer itself. Unlike other attacks that trick the AI with hidden text, here the extension bypasses the security barrier directly to the privileged agent. In some cases, it could read files from the computer, take screenshots, or turn on the camera; in all cases, it could make the agent act without any user clicks.
It’s also important to note the reassuring aspect: these are research demonstrations, not actual attacks, and each one assumes that the victim already has a malicious extension installed. The software vendors were notified and have paid bounties; fixes are already available for Chrome and Edge, with assigned vulnerability numbers (CVE-2026-0628 for Chrome, CVE-2026-55945 for Edge).
For a small business, the practical takeaway isn't to panic, but to practice good security. An AI agent in the browser is useful, but it opens a door that the browser would normally keep closed, and every additional extension is a potential key to that door.
What you need to do:
- Keep your browser up to date: Chrome version 143.0.7499.192 or newer, and Edge 150.0.4078.48 or newer. Updates usually install automatically when you restart your browser.
- Clean up your extensions: Remove any you don’t recognize or don’t use, and only install extensions from the official store by well-known developers.
- Decide who in the company can add extensions and enable an AI assistant in the work browser; the fewer extensions, the smaller the attack surface.
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This article was generated with AI assistance.