Jassy’s Calls Prompt U.S. Order to Disable Anthropic Models

Amazon CEO Andy Jassy raised security concerns about Anthropic’s Fable 5 with senior U.S. officials, prompting a federal order that led Anthropic to take Fable 5 and Mythos 5 offline and to bar access for foreign governments, firms and individuals.

Anthropic’s internal review found that Fable 5 could be coaxed, with a narrow set of prompts, into exposing technical details that might enable cyberattacks. The company reported the model surfaced security bugs in at least four software programs when given those specific inputs.

After Jassy alerted the administration, White House aides and national security and commerce officials met to consider options. Officials pressed Anthropic to either patch the vulnerabilities or remove the models from service; they settled on blocking foreign users as the most direct way to address export-control concerns. President Trump approved the restriction and expressed concern that it could slow technological innovation, according to administration sources.

National Cyber Director Sean Cairncross and Commerce Secretary Howard Lutnick took part in the discussions. The Commerce Department oversees export controls on sensitive technology, and government cyber officials began coordinating with Anthropic and outside researchers while the agency weighed enforceable remedies.

Anthropic pushed back, arguing the flagged problems were not unique to its models and that other systems could surface similar bugs without special bypasses. The company wrote that it disagreed recalls were warranted for a narrow potential jailbreak and added an apology to customers for the interruption as it worked to restore access.

Amazon is among Anthropic’s largest backers, having invested billions of dollars in the startup. The outage occurs as Anthropic prepares for a possible initial public offering; company executives warned a prolonged restriction could prompt users to migrate to competitors while the ban remains in effect.

Officials described the restriction as a temporary, enforceable measure tied to national security and export-control policy while vulnerabilities are addressed. Independent researchers and government teams continue to test the severity and replicability of the reported flaws.