Unauthenticated command execution via unsafe class deserialization

Insecure deserialization in Cinnamon AI Kotaemon 0.12.0 and earlier allows remote attackers to execute commands through check_connection. The handler merges attacker-controlled YAML or JSON into an LLM spec, lets type replace the class path, and calls deserialize with safe disabled, so importlib and getattr instantiate subprocess.check_output with supplied arguments. No account or interaction is required when the Gradio interface is network-reachable, and commands run with the application's process privileges, enabling access to its files, secrets, and data.