mythos-5

Anthropic disabled all customer access to its Fable 5 and Mythos 5 AI models on June 12, 2026, following a US government order citing national security concerns. The government mandated suspension of access for all foreign nationals, including Anthropic employees, based on evidence of a potential jailbreak method for Fable 5.

Anthropic disabled its Fable 5 and Mythos 5 AI models on Friday after receiving a U.S. government export control order at 5:21 p.m. ET. The directive, citing national security authorities, instructed the company to suspend all access by foreign nationals, including its own employees.