Commerce Department Restores Limited Mythos 5 Access but Keeps Fable 5 Restricted

The Commerce Department on June 27 permitted Anthropic to restore access to its Mythos 5 model for a limited number of trusted users. The move follows a four-month standoff between the administration and the company over security risks. Commerce Secretary Howard Lutnick wrote in a letter to Anthropic that the company "has worked with the U.S.

Government to address risks associated with" Mythos 5 and Fable 5. " Mythos 5 includes guardrails designed to deter use in cyberattacks or biological terror and has never been freely available. Axios reported that conversations between the administration and Anthropic are expected to continue over the weekend of June 27-28, with limits on Fable 5 potentially lifted as soon as the week of June 29.

Anthropic had described Fable 5 as the most capable model ever released to the public and made it available at no extra cost on paid Claude plans through June 22. Stripe used the model to overhaul a 50-million-line codebase in one day during early testing. On the same day the Commerce Department acted, OpenAI began a limited preview of GPT-5.6.

Axios reported that other agencies have determined Fable 5 can safely return, though the Pentagon and National Security Agency must still approve. Anthropic expects to restore Fable 5 access soon, according to a source close to the situation.