GHSA-8gj2-2cvc-6xx7: Flowise: Unauthenticated Credential Abuse via Text-to-Speech Endpoint Allows Unauthorized Use of Private Chatflow TTS Credentials

Flowise has a security flaw where the text-to-speech API endpoint doesn't require login and doesn't check if a chatflow is public before allowing access to it. An attacker who knows a chatflow's ID can trick the system into using that chatflow's stored API credentials (like OpenAI or ElevenLabs keys) to generate unlimited audio without permission, costing the real owner money.