Anthropic disables Fable and Mythos AI models after U.S. government bars it from giving foreigners access

Anthropic disables Fable and Mythos AI models after U.S. government bars it from giving foreigners access

Anthropic was forced to disable all access to its newest AI models, Fable 5 and Mythos 5, late on Friday after the U.S. Commerce Department used national security export controls to bar the company from distributing the models to any foreign national.

The directive includes not just people located outside the U.S., but also any foreign national in the U.S., including Anthropic’s own non-citizen employees.

Given the scope of the directive, Anthropic argued it had no choice but to disable the models for all users. It clarified that access to its less powerful Claude models, including its latest Claude Opus 4.8 model, was not affected.

“We apologize for this disruption to our customers,” Anthropic wrote in a post on X. “We believe this is a misunderstanding and are working to restore access as soon as possible.”

Anthropic said in a blog post that it received the directive at 5:21 pm Eastern Time. It said the letter it received “did not provide specific details” of the government’s national security concern.

But the company also said that officials had told Anthropic that the government made the decision after learning of a technique to bypass Fable 5’s safeguards. These safeguards were designed to prevent users from accessing the powerful cybersecurity abilities of Mythos, the underlying AI model on which Fable 5 is built.

Anthropic said it believed the jailbreak the government was citing was a narrow one that would unlock Mythos’s cybersecurity capabilities in only one specific instance and not a universal one that would defeat all of Fable 5’s safeguards. It also said it........

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