OpenHuman is an open-source agent harness available as a desktop application and Rust library. Before 0.56.0, the local server exposes the server-sent events endpoint at /events without bearer authentication, permits cross-origin browser access, and uses only a caller-supplied client_id to select WebChannelEvent objects from the process-wide event bus. An unauthenticated local client, or an attacker-hosted web page opened by the victim, can subscribe to another client's stream by supplying a known or guessed identifier; the fixed system identifier makes the proactive-message stream predictable. The exposed events can include complete assistant responses, streamed message content, tool names,