U.S. Orders Anthropic to Suspend Fable 5 and Mythos 5 Access for Foreign Nationals

Anthropic announced it will abruptly disable access to its newest models (Claude Fable 5 and Mythos 5) for foreign nationals after a U.S. government directive citing a potential narrow jailbreak technique; the company says the reported bypass identifies minor, previously-known vulnerabilities but that Mythos-class models can rapidly convert disclosed software flaws into working exploits, raising concerns about accelerated weaponization of vulnerabilities and prompting debate over export controls and model safeguards.