The Trump administration has lifted restrictions on Anthropic’s latest Claude chatbot versions, ending a weekslong ban tied to cybersecurity concerns. Anthropic said Tuesday night that its AI model called Claude Fable 5 is now widely available, and it is restoring access to its most powerful model, Mythos 5, but only to a select group of U.S.-based organizations approved by the federal government. The Commerce Department blocked foreign nationals from using both AI models on June 12, forcing the company to take the products down for all users days after unveiling them. Anthropic said the government’s concerns were sparked by a report from cybersecurity researchers at Amazon, its primary cloud computing provider, which “had found a method of bypassing Fable 5’s safeguards” enabling it to discover and potentially exploit software vulnerabilities. Officials grew increasingly concerned since Anthropic warned earlier this year that its Mythos model was adept at finding software flaws that could be weaponized by malicious hackers. Separately, OpenAI said Friday it is restricting the release of its new AI model, GPT-5.6 Sol, at the request of President Donald Trump’s administration, making it accessible only to a select group of government-approved customers for a temporary period. Trump last month signed an executive order on AI oversight establishing a framework for the federal government to vet national security risks of advanced AI systems for up to 30 days before public release, with participation described as voluntary.