Model
120d agoGPT-5.5 Matches Claude Mythos In Cyber Attacks
GPT-5.5 is the second model capable of autonomously solving a full network attack simulation. The UK AI Security Institute found its performance nearly equals Claude Mythos. While Anthropic limits Mythos to a small group, OpenAI already ships GPT-5.5 via ChatGPT and API.
The Signal
This increases the immediate availability of high-capability offensive tools.