Artificial intelligenceBoard member Paul Nakasone calls China 'most significant' cyberthreatOpenAI's new GPT-5.5-Cyber model is said to have capabilities similar to Anthropic's Claude Mythos. © ReutersREI NAKAFUJIMay 22, 2026 00:57 JSTTOKYO -- OpenAI is considering providing its new GPT-5.5-Cyber artificial intelligence model, which has advanced cybersecurity capabilities, to Japan amid the rapid rise of Chinese open-source models and the cyberthreats highlighted by Anthropic's Claude Mythos.