Anthropic Redeploys Claude Fable 5 After US Export Controls Lifted

Anthropic announced on June 30 that US export controls on Claude Fable 5 and Claude Mythos 5 have been lifted, with Fable 5 returning to global availability starting July 1. The suspension began on June 12 after the US government issued an export control directive following a report that Amazon researchers had discovered a method to bypass Fable 5’s safety safeguards, enabling the model to identify software vulnerabilities and produce exploit code.

Fable 5, originally launched on June 9, is Anthropic’s first publicly available Mythos-class model — a tier positioned above Opus. It scored more than 10% higher than Claude Opus 4.8 on key benchmarks and features a 1-million-token context window with 128K max output. The model is priced at $10 per million input tokens and $50 per million output tokens.

To address the safety concerns, Anthropic trained an improved safety classifier targeting the reported bypass, and now routes potentially unsafe requests to the less-capable Opus 4.8 instead. The company also announced an industry-wide framework — together with Amazon, Microsoft, Google, and other Glasswing partners — for scoring jailbreak severity, aiming to standardize how AI developers triage and communicate safety risks going forward.

Why it matters: The Fable 5 saga represents the first major test of government intervention in frontier AI model deployment, setting a precedent for how national security concerns, corporate responsibility, and global AI access will be balanced in an era of increasingly capable models.