Fable 5 stays dark on day nine as Anthropic and Commerce keep talking

Nine days after a 5:21pm Friday export-control letter pulled the model, refund deadlines hit and a UK carve-out collapses.

Claude Fable 5 and its parent model Mythos 5 are entering their ninth day offline for every Anthropic customer worldwide, with no restoration date and a Commerce Department export-control letter still governing the silence.

The letter arrived at 5:21pm ET on Friday, June 12, citing national security authorities and barring access by any foreign national inside or outside the United States. Anthropic complied that evening. The sequence that produced it’s the more interesting artifact. On Thursday night, Amazon delivered a report to administration officials demonstrating a jailbreak of Mythos. By Friday morning, at least five other companies had called senior officials. Administration staff then spent hours trying to convince Anthropic to pull the model voluntarily before the written order went out at the close of business.

Anthropic’s own characterization is that the issue is a “potential narrow, non-universal jailbreak” prompting the model to read a codebase and surface software flaws, a capability the company notes is also available in OpenAI’s GPT-5.5 and used daily by defensive security teams. The government, per Anthropic, has so far produced only verbal evidence.

Katie Moussouris, CEO of Luta Security, told Axios the response “seems way out of line with what’s actually in the research report.”

The commercial timing is its own story. Fable 5 launched June 9 at $10 per million input tokens and $50 per million output tokens, bundled into Pro, Max, Team and Enterprise plans through June 22, then scheduled to shift to usage credits on June 23. It’s been unreachable since day three. Subscribers are now hitting the end of an inclusion window for a product they can’t reach.

Commerce hasn’t commented publicly. The shape of the episode, an export-control instrument deployed inside 48 hours of a competitor’s jailbreak demo, is what regulators and rivals will study next.