AI-powered browser extensions now represent a systemic, undermonitored attack surface in enterprise environments, capable of harvesting credentials, exfiltrating sensitive data, and bypassing perimeter controls, all from within the trusted browser process. A documented Chrome vulnerability, detailed by Palo Alto Networks Unit 42, demonstrates concrete exploitation potential, showing how extensions can hijack active AI sessions such as Gemini Live. This threat signals a structural gap in enterprise security architecture: organizations that have invested heavily in network and endpoint controls may have left the browser, now a primary productivity environment, largely ungoverned.