Claude Fable 5 and Mythos 5 (Anthropic)

Was Claude Fable 5 banned?

Anthropic released Claude Fable 5 and Mythos 5 on June 9, and on June 12 the US government applied export controls to them. Because the order took effect immediately and Anthropic had no reliable way to verify nationality in real time, it suspended access to both models for all users. This was not a permanent ban. It is closest to the ChatGPT block in Italy: a sudden stop, then a return within weeks. anthropic

What the order covered

The order required Anthropic to suspend access by any foreign national, inside or outside the United States, including foreign national employees at Anthropic. Older models like Opus and Sonnet were not affected. Because it was issued on national-security grounds, it has more in common with the FCC restrictions on new Huawei and ZTE equipment than with the social media blocks in our Apps & Websites list. neowin

Why it happened

The government became aware of a report in which Amazon researchers had found a method of bypassing Fable 5’s safeguards by prompting it to identify software vulnerabilities. Anthropic said its testing showed that several less capable models could find the same vulnerabilities. You can read the company’s own account in its official redeployment statement. anthropic

Timeline

• June 9, 2026: Fable 5 and Mythos 5 launched.
• June 12, 2026: Export controls applied, access suspended for all users.
• June 26, 2026: US government approved Mythos 5 access for a set of US organizations. anthropic
• June 30, 2026: Export controls lifted.
• July 1, 2026: Fable 5 available again to users globally on the Claude Platform, Claude.ai, Claude Code and Claude Cowork. anthropic

See everything else on the USA banned list.