Anthropic Blocks Fable 5 and Mythos 5 Following U.S. National Security Directive

Anthropic has disabled worldwide access to its Fable 5 and Mythos 5 models after a U.S. government export-control directive citing a narrow jailbreak that can coerce the models into reviewing codebases and identifying minor, previously documented vulnerabilities; Anthropic contests the severity, says the issue is non-universal and limited in scope, and plans a technical disclosure while petitioning to restore access.