Your Browser Is a Backdoor to Your AI Agent

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AI agents increasingly run on developer machines with powerful local permissions. This white paper explains a critical but under-discussed risk: cross-origin WebSocket access to localhost, where any website a user visits can attempt connections to locally running services, without traditional CORS protections.

You’ll get a technical breakdown of how this browser-to-localhost gap can be chained with common implementation mistakes (incomplete Origin validation, implicit trust of loopback traffic, and weak/absent localhost rate limits) to escalate from a web page to authenticated control of a local AI agent gateway.

What you’ll learn

• Why WebSockets behave differently than fetch/CORS and how Origin checks fail in practice
• How localhost trust assumptions create silent escalation paths
• Concrete mitigation patterns for agent gateways and local developer tools
• What security teams should monitor when “shadow AI” appears on endpoints

Download the white paper to understand the mechanics and apply the safeguards.