ChatGPT 5.4 Cyber challenges Claude's Mythos with 1 million tokens

OpenAI's GPT-5.4 Cyber introduces advanced cybersecurity capabilities like binary reverse engineering, 1 million token context, and autonomous system interaction. With a 'cyber-permissive' approach and Trusted Access program, it enables broader yet controlled usage. Compared to Anthropic's restricted Mythos model, GPT-5.4 focuses on scalability and real-world deployment.