Anthropic has inadvertently revealed its most advanced AI model, Claude Mythos, following a configuration error that exposed nearly 3,000 unpublished assets. A draft blog post indicates that Mythos is intended to be a significant upgrade over the current top model, Opus, with capabilities in reasoning, coding, and cybersecurity. The draft suggested two potential names, Mythos and Capybara, indicating Anthropic's ongoing deliberation about branding. The company confirmed to Fortune that Mythos represents a "step change" in AI development, emphasizing its enhanced intelligence and capabilities. A critical concern raised in the draft is the potential cybersecurity risks associated with Mythos. The model is positioned as having advanced cyber capabilities that could enable attacks faster than current defenses. Anthropic has already faced real-world implications; a Chinese state-sponsored group previously exploited its Claude Code model to breach around thirty organizations. In response to these risks, access to Mythos will be limited initially to cybersecurity-focused organizations, allowing them to prepare before it becomes widely available. Mythos is also described as highly resource-intensive, raising questions about its cost-effectiveness and operational efficiency. Anthropic acknowledges the need for improvements before a general release, drawing a parallel to OpenAI's GPT-4.5, which faced similar challenges. There’s no set timeline for release, and it remains uncertain whether the model will be branded as Mythos, Capybara, or something else. For developers and businesses, the crucial factor will be whether the improved capabilities justify the likely high costs, or if it will primarily serve as a niche tool for well-funded enterprises.