AI company Anthropic has disabled customer access to its most capable systems, it said in a statement Friday night, after the U.S. government ordered it to cease all use by foreign nationals. The move is the latest in a series of adverse actions by the Trump administration targeting the company.
Anthropic’s extensive directive for Mythos 5 and Fable 5 models is one of the most far-reaching steps the government has taken in response to the advanced capabilities of AI models.
Antropic said the U.S. government issued the directive citing “national security” issues.
The company said it believed the government had “realized” a way to “jailbreak” Fable 5, or circumvent domestic security fences, although the government did not provide specific details about national security concerns.
“We have reviewed a demonstration of this particular technology used to identify a small number of known minor vulnerabilities,” Anthropic said in a statement. “Although these vulnerabilities all seem relatively simple, we found that other publicly available models can detect them as well without the need for bypass.”
Anthropic said it has implemented several safety measures on its latest models to “significantly reduce the likelihood” that the company’s latest models “will be exploited for cybersecurity-related operations,” noting that it has received complaints from users that these guardrails are too strict. Anthropic also said it is working with the U.S. government to “red team” Fable’s safeguards, and that no model is completely immune to any jailbreak.
Anthropic said it is removing access to the model for everyone in accordance with the directive, but “does not agree that the discovery of a narrow jailbreak possibility should be grounds for recalling a commercial model that has been deployed to hundreds of millions of people.”
“We believe that if this standard were applied industry-wide, it would effectively halt the rollout of all new models to all Frontier model providers,” the company added.
This restriction means that many foreigners working at Anthropic cannot touch these models.
The Department of Commerce, which issued the restrictions, did not respond to a request for comment. Axios reported that a government directive would require Anthropic to obtain a license to “export, reexport, or internally transfer Anthropic models.”
Anthropic’s latest model, Mythos, has surprised the U.S. government and Wall Street with its capabilities, which experts say can exploit cybersecurity vulnerabilities at an unprecedented pace. This model was considered so capable that Anthropic initially limited its release to a group of key partners in order to “protect the world’s most important software.” Anthropic released Fable 5 last week as a version of Mythos safe for general use.
The model also inspired the Trump administration’s recent AI executive order, which requires companies to voluntarily share new models deemed to have advanced cyber capabilities with the government 30 days before providing access to other partners.
A person with knowledge of early discussions about the executive order said the idea was floated that it would ban foreigners from working on such models, but that idea was not included in the draft.
The government has a complicated relationship with Anthropic. Earlier this year, the Trump administration declared Anthropic a “supply chain risk” in military transactions and blacklisted the company over its insistence that the Pentagon establish certain safeguards against the government’s use of AI in warfare. Anthropic sued the government over the designation, calling it “unprecedented and illegal,” and has achieved at least one early victory in an ongoing lawsuit.
Despite then-President Donald Trump’s directive to all federal governments to cease handling Anthropic products, the White House remained in close contact with the company, and some in the federal government found workarounds to continue accessing Anthropic’s models, especially after the release of Mythos.
A person familiar with the situation told CNN that Anthropic was also heavily involved in drafting the latest executive order, and its executives were invited to the White House for the signing ceremony, which was ultimately canceled at the last minute.
