Claude Mythos 5 Gets Green Light for 100+ US Institutions — Is Fable 5 Next?

The US Department of Commerce has lifted its export restrictions on Anthropic's Claude Mythos 5, clearing the advanced AI model for deployment across more than 100 American institutions, including major corporations and federal agencies. The decision, announced on a Friday, ends a two-week standoff between the Trump administration and AI startup Anthropic.

Commerce Secretary Howard Lutnick formally communicated the decision in a letter addressed to Anthropic's compute chief Tom Brown. According to the letter, a license is no longer required to export Mythos 5 to entities listed in Annex A. Lutnick stated that "appropriate safeguards are in place to permit certain trusted partners to access the Claude Mythos 5 Model," signaling that the administration is satisfied with the security measures surrounding the model's distribution.

Senior Anthropic executives had reportedly traveled to Washington during the standoff to hold direct talks with administration officials, according to CNBC. Their efforts appear to have paid off — at least partially. While Mythos 5 is now cleared, its consumer-facing counterpart, Fable 5, remains offline pending further review.

The initial block stemmed from concerns raised by Amazon, one of Anthropic's biggest backers. Amazon researchers had warned that Fable 5 could be manipulated through jailbreaking techniques for harmful purposes. The restrictions forced both models offline simultaneously, disrupting access for users and organizations alike.

Before the lockdown, Claude Mythos 5 was already operating within Project Glasswing, a vulnerability-discovery initiative spanning roughly 150 organizations across more than 15 countries. The model had demonstrated notable capability earlier, reportedly identifying security flaws in classified government systems within just hours of testing.

Sources close to the negotiations indicate that a Fable 5 release is progressing, though no firm timeline has been set. Unlike Mythos, Fable 5 had been publicly accessible to anyone with a subscription and briefly held the distinction of being the most capable AI tool available to the general public.

The episode is reshaping how the US government approaches frontier AI oversight. A June 2 executive order established a voluntary federal review channel for advanced AI models, allowing developers to submit their systems for a cybersecurity evaluation up to 30 days before launch. This marks a notable expansion of Washington's AI gatekeeping authority — previously focused on hardware exports like chips to China — now extending to model-level access control.

OpenAI followed a similar trajectory on the same day, restricting its most powerful GPT-5.6 tier, known as Sol, to approximately 20 government-approved partners, while making the less capable Terra and Luna versions publicly available.

The original concerns behind the Mythos and Fable block were also linked to fears over potential Chinese access, with reports pointing to SK Telecom — a South Korean telecom company added to the Glasswing program in early June before losing access. SK Telecom has publicly denied any connections to China.

In response to the restrictions, dozens of cybersecurity leaders signed an open letter calling on the administration to remove the controls. The letter, organized by Alex Stamos, former chief security officer at Facebook, gathered signatures from executives at Nvidia, Adobe, Zoom, and other major technology firms.

The restrictions have also stirred frustration among US allies in Europe and elsewhere, who found themselves suddenly dependent on Washington's approval to access cutting-edge AI tools. Whether Fable 5 will receive the same clearance as Mythos 5 may become clear within the coming days.