technologySunday, June 14, 20262 sources

US Government Bans Access to Anthropic's Fable 5 and Mythos 5 Models

The US government banned foreign access to Anthropic's advanced AI models, Fable 5 and Mythos 5, citing national security concerns. Amazon's research reportedly influenced the decision, with CEO Andy Jassy informing officials of vulnerabilities that could enable sensitive data extraction. Anthropic complied with the ban but warned of slowed AI progress.

On June 14, 2026, the US government ordered Anthropic to halt access to its Fable 5 and Mythos 5 models, citing minor software vulnerabilities that could allow sensitive information to be extracted. Amazon's research, reportedly conducted by its team, was said to have informed US officials about these potential risks. The Trump administration claimed the vulnerabilities posed a threat to national security, though Anthropic stated the issues were minor and publicly known.

Timelines

Sources

IndependentTimes of IndiaJun 14, 12:32 PM
Ban on Fable 5: Anthropic received this instruction over a call from US govt on Friday

The Trump administration has ordered AI firm Anthropic to halt its advanced models Fable 5 and Mythos. Officials cited national security concerns after researchers found minor software vulnerabilities. Anthropic disagrees, stating the issues were known and minor. The company complied but hopes for restored access, warning of slowed AI progress.

IndependentTimes of IndiaJun 14, 11:45 AM
Amazon CEO’s conversation with US officials that led to Anthropic's Fable 5 ban

Amazon's research reportedly influenced the US government's decision to block foreign access to Anthropic's advanced AI models, Fable 5 and Mythos 5. CEO Andy Jassy allegedly informed officials that Amazon researchers found ways to extract sensitive information, potentially aiding cyberattacks, from these models. Anthropic stated the vulnerabilities exposed were minor and publicly known.