Overview
- Anthropic confirmed Tuesday that the Department of Commerce has withdrawn export restrictions and that it will begin restoring global access to Fable 5 and reinstating Mythos 5 for approved partners.
- The controls were placed on June 12 after Amazon researchers reported a prompt technique that could bypass Fable 5’s guardrails and coax the model to identify software vulnerabilities.
- Anthropic trained and deployed a targeted safety classifier that the company says blocks the reported bypass more than 99 percent of the time and reroutes flagged requests to an older model, Opus 4.8.
- Before the full lift, U.S. officials had already allowed Mythos 5 to return for roughly 100 vetted American organizations focused on critical infrastructure and cyber defense.
- The episode sets a precedent for government pre-release review of cloud-hosted models, is accelerating interest in downloadable open-weight models as a hedge against centralized revocation, and may widen cooperative testing and reporting standards across industry and agencies.