tl;dr: The US Commerce Department lifted its two-week export block on Anthropic's Claude Mythos 5, permitting release to ~100 approved US institutions and foreign national employees listed in an annex. The block was originally imposed after Amazon and others warned the model could be jailbroken for malicious use; the weaker Fable 5 remains restricted but may follow. The move coincides with OpenAI releasing GPT-5.6 to a similar list of government-approved partners.