CVE-2026-85695 [CRITICAL] – FastChat contains an authentication bypass vulnerability in the /register_worker endpoint

FastChat contains an authentication bypass vulnerability in the /register_worker endpoint that allows unauthenticated attackers to register arbitrary worker addresses and perform server-side request forgery. Attackers can register malicious workers under victim model names to intercept user prompts, images, and responses, or probe internal network ports across the worker mesh.