The company said late Friday that the directive left it with no practical way to keep the models online while ensuring compliance.
“The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees,” Anthropic said in a statement.
The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees.
The net effect of…
— Anthropic (@AnthropicAI) June 13, 2026
“The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance,” the company added.
Visitors to the Claude chatbot website encountered a notice Friday evening stating that “Fable 5 is temporarily unavailable.”
The order, issued by Commerce Secretary Howard Lutnick with input from the Bureau of Industry and Security, appears to mark the first time the federal government has forced a major artificial intelligence company to withdraw a widely available model because of national security concerns, writes NBC News.
Anthropic said the government identified a technique that could potentially bypass certain safeguards in Fable 5. However, the company said federal officials provided only “verbal evidence” of the vulnerability and indicated that similar weaknesses likely exist in models developed by other companies.
“We disagree that the finding of a narrow potential jailbreak should be cause for recalling a commercial model deployed to hundreds of millions of people,” Anthropic said.
Anthropic released Fable 5 and Mythos 5 on Tuesday, describing them as its most advanced systems to date. The models use the same underlying architecture but were designed for different audiences.
Fable 5 was made available to the public with additional protections intended to prevent misuse in sensitive areas such as cybersecurity and biological research. Mythos 5, which lacks some of those restrictions, was distributed only to a limited group of trusted partners, including cybersecurity and infrastructure companies.
When it released the models earlier this week, Anthropic acknowledged that the systems posed potential risks.
“Releasing a model this capable comes with risks. Without safeguards, Fable 5’s capabilities in areas like cybersecurity could be misused to cause serious damage,” the company said at the time.
Anthropic characterized the Commerce Department’s action as the result of “a misunderstanding” and said it hoped to restore access quickly. The company also criticized the process used to issue the directive.
“We believe the government should have the ability to block unsafe deployments, as part of a statutory process that is transparent, fair, clear, and grounded in technical facts. This action does not adhere to those principles,” Anthropic said.
The dispute adds to an already tense relationship between Anthropic and the Trump administration. Earlier this year, the company faced restrictions on federal use of its technology after pressing for stronger limits on military applications of artificial intelligence. Anthropic challenged those restrictions in court and won a partial victory, although the case remains unresolved.
More recently, signs of cooperation had emerged, including reports that the National Security Agency was using Mythos for offensive cyber operations.
