US export order cuts off Fable 5 and Mythos 5 access for Anthropic users

Anthropic’s Fable 5 and Mythos 5 disruption turns frontier-model access into a live export-control issue. In a June 13, 2026 tweet at 00:50 UTC, the company said the US government had used national-security authorities to suspend foreign-national access to both models, including access by foreign-national Anthropic employees.

The substantive line was blunt: Anthropic said it must disable the models for all our customers. The company added that access to other Claude models was not affected. The scale of attention was unusually high for a policy notice: FxTwitter showed more than 51 million views, 67,000 likes, and 21,000 reposts.

The linked company statement adds important context. Anthropic says it received the directive on June 12 at 5:21 p.m. ET and that the letter did not provide specific details of the national-security concern. Its understanding is that the government had seen a method for bypassing, or jailbreaking, Fable 5. Anthropic argues the demonstrated technique identified a small number of previously known, minor vulnerabilities that other public models could also find.

Anthropic’s official account usually publishes Claude product updates, safety research, and policy statements. This post is more consequential than routine model messaging because it affects customer availability and employee access immediately. What to watch next: whether the US government narrows or withdraws the order, whether Anthropic releases more evidence about Fable 5 safeguards, and whether comparable access restrictions reach other frontier-model providers. Source tweet