Anthropic Restores the Mythos Model to US Critical Infrastructure Operators

IBL News | New York

Anthropic’s Mythos 5 is partially back, as about 100 trusted US organizations, primarily cybersecurity companies and critical infrastructure providers, do have access. Project Glasswing members, including Apple, Google, Cisco, Nvidia, and Microsoft, are authorized.

• API users and international customers are still limited to older Claude models.
• Fable 5, the general-use version, remains offline for everyone else.

The company’s two most powerful AI models got pulled offline two weeks ago under a US government directive. Currently, Anthropic is actively negotiating to bring Fable 5 back for general use.

Claude Mythos 5 is Anthropic’s strongest cybersecurity model. It can autonomously find software vulnerabilities at a scale, such as thousands of high-severity flaws across every major OS and browser, including a 27-year-old OpenBSD bug and chained Linux kernel exploits.

That power is why it got locked down. The concern is that bad actors could use it to attack systems just as fast as defenders use it to protect them.

Since June 12, we’ve been working closely with the US government to restore access to Claude Mythos 5 and Fable 5. Today, the government notified us that Mythos 5, our strongest cybersecurity model, can be redeployed to a set of US organizations that operate and defend critical…

— Anthropic (@AnthropicAI) June 27, 2026