While much of the discussion on AI security centers around protecting ‘shadow’ AI and GenAI consumption, there's a wide-open window nobody's guarding: AI browser extensions. A new report from LayerX exposes just how deep this blind spot goes, and why AI extensions may be the most dangerous AI threat surface in your network that isn't on anyone's radar. The first misconception is that extensions are a niche risk. Something limited to a subset of users or edge cases. That assumption is completely wrong. According to the report, 99% of enterprise users run at least one browser extension, and more than a quarter have over 10 installed. This is not a long tail problem; it is universal. Yet most organizations cannot answer basic questions. Which extensions are in use? Who installed them? What permissions do they have? What data can they access? Security teams have spent years building visibility into networks, endpoints, and identities. Ironically, browser extensions remain a major blind spot. While much of the current conversation around AI security focuses on SaaS platforms and APIs, this report highlights a different and largely ignored channel: AI browser extensions. These tools are spreading quickly. About 1-in-6 enterprise users already use at least one AI extension, and that number is only growing. Organizations may block or monitor direct access to AI applications. But extensions operate differently. They sit inside the browser. They can access page content, user inputs, and session data without triggering traditional controls. In effect, they create an ungoverned layer of AI usage, one that bypasses visibility and policy enforcement.