In brief
Claude Fable 5 is set to return globally on Wednesday, nearly three weeks after a U.S. export control directive forced Anthropic to pull it and sibling model Mythos 5 offline worldwide.
Anthropic built a new safety classifier that blocks the reported jailbreak technique in over 99% of cases.
Anthropic is drafting a jailbreak-severity framework with Amazon, Microsoft, and Google, and pledged earlier government access to future frontier models before release.
Claude Fable 5 is coming back. Anthropic said the model will return to users globally on Wednesday across Claude.ai, the Claude Platform, Claude Code, and Claude Cowork, after the U.S. Commerce Department lifted the export controls that had forced it offline since June 12.Mythos 5, the more capable sibling model built on the same underlying system, will remain limited to vetted partners.“On Friday, June 12, the U.S. government applied export controls to our newest models, Claude Fable 5 and Claude Mythos 5. This required us to restrict access to foreign nationals, whether inside or outside the United States,” Anthropic wrote in a blog post late Tuesday. “As of today, June 30, the export controls on Fable 5 and Mythos 5 have been lifted.”The shutdown traced back to a jailbreak report from Amazon researchers, who found a way to bypass Fable 5's guardrails and get the model to identify software vulnerabilities. In one case, the model produced code demonstrating how to exploit one of them. Since the export order applied to all foreign nationals anywhere in the world and Anthropic had no real-time way to verify nationality user by user, the company disabled both models for every user rather than risk noncompliance.
