Anthropic announced that Claude Fable 5 will be restored globally on Wednesday, June 30, after the U.S. Commerce Department lifted export controls that had forced the model offline since June 12 due to a jailbreak report from Amazon researchers. The researchers found a bypass technique allowing the model to identify software vulnerabilities, leading to export restrictions on all foreign nationals. To comply, Anthropic disabled both Fable 5 and its more capable sibling Mythos 5. Anthropic has now retrained a safety classifier that blocks the reported bypass in over 99% of cases, with flagged requests rerouted to Claude Opus 4.8. However, access details have changed: Pro, Max, Team, and select Enterprise subscribers get Fable 5 included at 50% of weekly usage through July 7, a reduction from the original full inclusion for 13 days. Mythos 5 remains limited to vetted partners. The blackout allowed rivals like OpenAI's GPT-5.5-Cyber to surpass Mythos 5 on a cybersecurity benchmark. Anthropic is now working with Amazon, Microsoft, and Google to develop a jailbreak severity framework and has committed to earlier government access for future frontier models. A new HackerOne program encourages researchers to report bypass techniques.

Key facts

• Claude Fable 5 returns globally June 30 after US lifts export controls imposed June 12.
• Anthropic retrained safety classifier blocks reported jailbreak in over 99% of cases.
• Access reduced: 50% weekly usage cap for six days vs. original 13-day full inclusion.
• Mythos 5 remains restricted to vetted partners only.
• Anthropic partners with Amazon, Microsoft, Google on jailbreak severity framework.