Anthropic's Fable model, part of its Mythos series, has come under government regulation after a security flaw was discovered and left unresolved. David Sacks, co-chair of the U.S. President's Council of Advisors on Science and Technology, highlighted the issue in a tweet, noting that a trusted partner found a method to bypass the model's safeguards. Despite requests to fix the vulnerability, Anthropic refused, leading to government intervention to prevent the model from reaching unauthorized users. The government is urging Anthropic to address the flaw promptly to lift the restrictions and resume normal operations.