







Only three days after the release of Claude Fable 5, Anthropic was forced by the United States Government to make it unavailable, when a jailbreak was brought to its attention, rather than the previous situation of ‘yes obviously experts can jailbreak anything if they care enough’ and ‘yes obviously you can ask Fable to fix your code.’
Redeploying Claude Fable 5
Anthropic is redeploying Claude Fable 5 starting July 1 following the lifting of export controls, with updated cybersecurity safeguards and a new industry jailbreak framework.

More details on Fable 5’s cyber safeguards and our jailbreak framework
What is and isn't blocked by our cyber classifiers, and a first draft of our jailbreak severity framework
Anthropic releases Claude Fable, a version of Mythos, days after warning AI is becoming too dangerous
Anthropic is releasing Claude Fable 5, its first Mythos-class model available to the public. The model comes with guardrails that block responses in high-risk areas like cybersecurity and biology.

Anthropic disables access to Fable 5 and Mythos 5 to comply with government directive
Anthropic said it disabled access to its Fable 5 and Mythos 5 models to comply with an export control directive from the U.S. government.

Claude Fable 5 and Claude Mythos 5
Today we’re launching Claude Fable 5: a Mythos-class model that we’ve made safe for general use.

Anthropic cuts off Fable 5 and Mythos 5 access following government order
The US demanded foreign nations be blocked over national security concerns.

Anthropic says it is disabling Fable 5 and Mythos 5 for all customers after the US government issued an export control order, citing national security concerns
Anthropic: Anthropic says it is disabling Fable 5 and Mythos 5 for all customers after the US government issued an export control order, citing national security concerns

Anthropic on Twitter / X
Claude Fable 5 will be available again globally tomorrow.After a series of productive conversations with the US government, we're redeploying the model with a new set of classifiers to target and block more cybersecurity tasks. In the near term, some routine tasks like coding…— Anthropic (@AnthropicAI) July 1, 2026
The Once And Future Fable #2
On Friday evening the United States Government has forced Anthropic to take down all access to Fable and Mythos.

Claude Fable 5 and Mythos 5: The System Card
First things first: Claude Fable 5 is the new best publicly available model.

Anthropic’s Mythos 5 is back
Anthropic’s Mythos 5 model, the subject of weekslong negotiations with the Trump administration, is back in action. No word yet on Fable 5.

Three Labs With a Plan and A Memorandum
The big story today is the release of Claude Fable 5, the version of Claude Mythos that Anthropic believes they can safely distribute to the people.

Anthropic on Twitter / X
The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees.The net effect of…— Anthropic (@AnthropicAI) June 13, 2026
Introducing Claude Fable 5.1 on AWS | Amazon Web Services
Claude Fable 5.1 is now available on Amazon Bedrock and Claude Platform on AWS. This post covers Claude Fable 5.1's improvements, the Enterprise Frontier Safeguards for keeping your data in a cloud environment you control, and how to start building with the model on Amazon Bedrock.

Anthropic published a jailbreak severity framework — co-developed with Glasswing partners — 3 days after the model it was sanctioned for came back online. The framework is substantive and the ban was likely overblown. Both true. But whoever writes the rubric defines what counts as an incident.