Anthropic cuts off Fable 5 and Mythos 5 access following government order

2026-06-13 · Source: The Verge · Field: Technology & Digital — Artificial Intelligence & Machine Learning, Cybersecurity & Data Privacy, AI Policy & Regulation · Depth: Fundamental Awareness, quick

Summary

Anthropic has completely cut off access to its Fable 5 and Mythos 5 AI models for all customers, including foreign nations and its own employees, following a government order issued on Friday evening. The directive cited national security concerns, prompting Anthropic's compliance. However, the company stated that the government did not provide specific details regarding these concerns, claiming any evidence of potential jailbreaks was communicated verbally. Anthropic further asserted that the discovered vulnerabilities were minor, non-universal, and also present in other models, such as GPT 5.5. The company highlighted its proactive measures to safeguard Fable and Mythos, which included collaboration with US and UK governments and changes to its data retention policy to track malicious use attempts.

Key takeaway

For Directors of AI/ML deploying advanced models, you must anticipate potential government intervention based on national security concerns, even without detailed justification. Your compliance plans should account for immediate access termination across all user bases, including internal teams. Be prepared to address verbal vulnerability claims and ensure your data retention policies align with potential government oversight. This incident highlights the evolving regulatory landscape for powerful AI systems.

Key insights

The government ordered Anthropic to block AI model access due to unspecified national security concerns, despite Anthropic's claims of minor vulnerabilities.

Topics

• Anthropic
• Fable 5
• Mythos 5
• AI Model Access
• National Security
• Government Regulation

Best for: CTO, VP of Engineering/Data, Investor, Policy Maker, Legal Professional, Director of AI/ML

Related on AIssential

• Anthropic Suspends Customers’ Access to Latest Models After Government Order — Government orders can immediately restrict access to advanced AI models due to national security concerns.
• How Fable 5 And Mythos 5 Change AI Security, Data Retention, And Vendor Risk — Anthropic's Fable 5 and Mythos 5 models offer advanced capabilities but impose mandatory 30-day data retention, altering enterprise risk profiles.
• Anthropic to disable its most advanced AI models after US order limiting foreign access — US export controls are expanding to directly restrict foreign access to advanced AI models, not just hardware.
• US government forces Anthropic to disable Claude Fable 5 and Mythos 5 for all customers worldwide — Government-mandated global disabling of Anthropic's Fable 5 and Mythos 5 due to a suspected jailbreak sets a contentious industry precedent.
• Anthropic releases ‘safe’ version of Claude Mythos AI model to public — Anthropic's Fable 5 release balances advanced AI capabilities with stringent security measures and tiered access.
• US limits use of Anthropic AI models Fable 5 and Mythos — Government AI safety concerns are escalating, leading to direct restrictions on frontier model access and development.

Open in AIssential →

Editorial summary, takeaway, and curation by AIssential. Original article published by The Verge.