U.S. Government Orders Anthropic to Cut Off Access to Fable 5 and Mythos 5

*Anthropic disables two models worldwide after an export control directive bars any foreign national from using them.*

The Directive

Anthropic received the order at 5:21 p.m. Eastern Time. The U.S. government invoked national security authorities to require immediate suspension of access to Fable 5 and Mythos 5 for every foreign national, whether located inside or outside the United States. This includes foreign employees at Anthropic itself. To meet the requirement, the company turned the models off for all customers.

Access to every other Anthropic model remains unchanged. The directive contained no further technical details on the precise risk.

What Anthropic Knows

Anthropic’s statement says the government appears to have learned of a jailbreak technique that works against Fable 5. Company engineers reviewed a demonstration of that method. No additional information on the technique or its scope was shared in the letter.

The company framed the shutdown as a compliance step rather than a voluntary action. It did not indicate when, or whether, service might resume.

Why It Matters

Export controls have previously targeted chips and software code. Extending them to live model weights marks a sharper boundary between domestic and foreign use of frontier systems. Companies that host such models now face the same compliance burden that hardware exporters have carried for years. The abrupt, worldwide cutoff shows how quickly a single government order can remove a capability that thousands of users relied on.

---

Sources:

• Daring Fireball

{
  "excerpt": "Anthropic disables Fable 5 and Mythos 5 worldwide after a U.S. export control order bars foreign nationals from access on national security grounds.",
  "suggestedSection": "security",
  "suggestedTags": ["anthropic", "export-controls"],
  "imagePrompt": "An empty server rack in a dim concrete room, one blank drive tray pulled halfway out, thin cables trailing across the floor. Muted color palette, cinematic lighting, 16:9."
}