GPT-5.5 Rivals Claude Mythos in Cyberattack Simulations, UK AI Security Institute Reports
OpenAI’s GPT-5.5 has demonstrated autonomous proficiency in complex network attack simulations, matching the performance of Anthropic’s Claude Mythos, according to findings from the UK AI Security Institute. Available through ChatGPT and API, GPT-5.5 sets a new benchmark in AI-driven cybersecurity.