OpenAI Has a New GPT-5.4-Cyber Model. Here's Why You Can't Use It
… Unlike Claude Mythos Preview, which Anthropic said is an entirely new model, OpenAI's GPT-5.4-Cyber is a fine-tuned version of its existing GPT-5.4 large language model. It's been adjusted to focus specifically on cybersecurity and has lower guardrails for security tasks. …