Anthropic has decided to indefinitely withhold its advanced AI model, Claude Mythos Preview, from public and commercial release due to security concerns. Despite the model's exceptional capabilities in vulnerability discovery and cyber defense, the company cites the potential risks of weaponization as a primary reason for this decision. The model's unrestricted release could significantly lower the cost of developing malware and launching cyberattacks, posing severe threats to global internet infrastructure. In collaboration with partners like Microsoft and Oracle, Anthropic's Mythos Preview identified over 10,000 high-severity vulnerabilities in critical infrastructure during recent tests. The UK AI Safety Institute noted that Mythos Preview is the first model to breach all simulated cyber defense ranges. While the model has dramatically improved vulnerability discovery efficiency, the security sector faces a "patch overload" due to the sheer volume of vulnerabilities identified.