Claude Mythos Preview is a next-generation language model designed with exceptional capabilities in cybersecurity analysis and exploit development. It has demonstrated the ability to autonomously identify zero-day vulnerabilities in major operating systems, web browsers, and widely used software. The model can go beyond detection by constructing functional exploits, including remote code execution and privilege escalation chains. It uses agentic workflows to explore codebases, test vulnerabilities, and validate findings without human intervention. Mythos Preview can also reverse engineer closed-source binaries, reconstructing logic and identifying potential weaknesses. Compared to earlier models, it shows a dramatic improvement in exploit success rates and complexity handling. The model is capable of chaining multiple vulnerabilities together to bypass modern security defenses. It can assist both defenders and attackers, depending on how it is used, highlighting the dual-use nature of advanced AI systems. These capabilities have led to initiatives focused on strengthening cybersecurity defenses using the model. Overall, Claude Mythos Preview represents a major advancement in AI-driven security research and automation.