Flowise before 3.1.4 fails to validate chatflow visibility in the unauthenticated text-to-speech endpoint, allowing attackers to abuse private chatflow TTS credentials. Unauthenticated attackers can generate unlimited text-to-speech audio using stored OpenAI or ElevenLabs API keys by providing a valid chatflow UUID, incurring costs on the chatflow owner's account.
Analyzing vulnerability vectors…