01What Is the Claude Mythos Leak?

Claude Mythos leak refers to the unauthorized public exposure of nearly 3,000 internal Anthropic files, including a draft blog post about their new AI model, Claude Mythos. The files were discovered in a publicly searchable database because someone forgot to change a privacy setting. The draft describes Mythos as 'by far the most powerful AI model we've ever developed,' and it introduces a new model tier called Capybara, which sits above Opus.

The leak was found by cybersecurity researcher Alexandre Pauwels from the University of Cambridge and independently reviewed by Ray Paz from Layer X Security. Anthropic later confirmed the model's existence, calling it a 'step change' and the most capable model they've built to date. The discovery has major implications for AI safety and the future of work.

02Key Features of Claude Mythos

Claude Mythos is not just an upgrade; it's a new category of AI. Here are the main features revealed in the leaked documents:

  • New model tier (Capybara): This tier is bigger and more expensive than Opus, the current top model.
  • Superior scores: Mythos scores 'dramatically higher' than Claude 4.6 on coding, academic reasoning, and cybersecurity.
  • Advanced cyber capabilities: Dream says Mythos is 'far ahead' of any other AI in cyber capabilities, able to exploit vulnerabilities faster than defenders can respond.
  • Step-change performance: Anthropic confirmed it's a 'step change' and the most capable model to date.

These features mean Mythos is designed for tasks requiring deep analysis, complex problem-solving, and rapid vulnerability discovery. The model is already in testing with a small group of early access customers.

03How the Leak Happened and How to Get Access

Getting access to Claude Mythos is not straightforward, but knowing how the leak happened can teach you about AI security. Here's what happened:

  1. Default setting left files public: Anthropic's content management tool had a default that made uploaded files public unless manually changed to private.
  2. Someone uploaded internal files: Nearly 3,000 files were uploaded without changing the setting.
  3. Researchers found them: Alexandre Pauwels and Ray Paz independently discovered the files in a public database.
  4. Anthropic locked the database: After Fortune contacted them, Anthropic pulled access, but the info was already out.

To use Claude Mythos when it launches, you'll need to stay updated on Anthropic's official announcements. Early access is currently limited to cyber defense organizations to give defenders a head start.

04How to Use Claude Mythos for Your Business

While Claude Mythos isn't publicly available yet, you can prepare by understanding its capabilities. The model's higher academic reasoning and coding scores mean it can produce deeper research, better strategy decks, and more nuanced analysis than current tools.

  • For content creation: Use it to plan content series, develop course curricula, or write long-form articles with better insight.
  • For coding: It can identify vulnerabilities or write more complex code, improving your software's security and development.
  • For cybersecurity: It can find and patch vulnerabilities faster, but also poses risks if used maliciously.

Even before Mythos lands, start building AI workflows with current Claude models. That way, you'll be ready to run faster when the new model arrives.

05Results and Comparisons from the Episode

In the episode, Julian Goldie compared Claude Mythos to other AI models. He noted that just weeks before, OpenAI released GPT-5.3 Codex, which was the first model classified as 'high capability' for cybersecurity. That same week, Anthropic released Opus 4.6, which was already finding unknown vulnerabilities in real production code.

Mythos makes both of those look like early drafts. The leaked draft shows dramatically higher scores on coding, academic reasoning, and cybersecurity compared to Opus 4.6. Anthropic also reported a campaign by a Chinese state-sponsored group using Claude code to infiltrate 30 organizations, but that was with Opus-level, not Mythos level, capability.

The message is clear: each new model raises the ceiling, and the pace is accelerating. Businesses that ignore this will be left behind.

06Tips, Limits, and Mistakes to Avoid

In this episode, Julian highlighted several important points:

  • Don't underestimate the security risk: Mythos can outpace defenders, meaning by the time you know there's a problem, it's already exploited.
  • Don't assume you're safe: If you have an online presence, you're part of the environment that's shifting.
  • Avoid waiting to build AI skills: The businesses that adapt first get the advantage.
  • Don't ignore the reasoning capabilities: Security is scary, but the academic reasoning boost has broad business applications.

The biggest mistake is doing nothing. The episode stresses that businesses need to build AI fluency now to be ready for Mythos when it arrives.

07Who Should Care About Claude Mythos and Why

Anyone running a business online should care about Claude Mythos leak. Whether you have a website, client portal, Shopify store, or course platform, the AI landscape affects your operations. Julian explains that the businesses already fluent with AI will get far more value from new tools.

For marketers, better reasoning means better research, strategy, and content. For developers, it means faster coding and vulnerability fixes. For cybersecurity teams, it's a double-edged sword—both a threat and a tool.

The episode promotes the AI Profit Boardroom as a resource to help you build these skills, but the core message applies to everyone: adapt now or catch up later.