On June 12, 2026, a US export control directive forced Anthropic to disable Claude Fable 5 and Mythos 5 worldwide after a narrow jailbreak was found that made the models reveal code flaws. The shutdown was driven by deemed-export rules that treat model output shown to a foreign national as an export, making a global off switch the only compliant option. #Anthropic #ClaudeFable5 #Mythos5 #DeemedExport #USCommerce
Keypoints
- A June 12, 2026 directive forced Anthropic to disable Claude Fable 5 and Mythos 5 globally.
- The trigger was a narrow jailbreak that asked the model to review code and find flaws.
- Commerce restricted access for any foreign national, including Anthropic’s own foreign-national employees.
- Anthropic said the models could not reliably verify user nationality in real time, making blanket shutdown necessary.
- The case exposed how deemed-export rules collide with frontier models that generate new output on demand.
Read More: https://www.toxsec.com/p/fable-5-export-control-takedown-one