NASA’s new dark energy space telescope can also detect killer asteroids
technologyreview.com·2h ago
Data Science
Simon Willison's Blog·Jun 13·5 min read
Statement on the US government directive to suspend access to Fable 5 and Mythos 5
TL;DR
The US government has suspended access to the AI models Fable 5 and Mythos 5 due to national security concerns. This decision was prompted by a potential method to bypass security measures, referred to as 'jailbreaking.'
✦ Why It Matters
Engineers should be aware of potential compliance issues when developing AI models and the importance of security measures.
Key Takeaways
- Review compliance with the new US government directive.
- Consider alternative models for projects involving foreign nationals.
- Stay updated on further announcements from Anthropic.
- Assess the impact of this suspension on your current projects.
Full Summary
On June 13, 2026, the US government issued a directive to suspend access to Anthropic's AI models, Fable 5 and Mythos 5, for all foreign nationals, including employees of Anthropic. This action was taken based on national security concerns related to a potential 'jailbreak' method that could exploit minor vulnerabilities in the models.
Anthropic received the directive without specific details but noted that the vulnerabilities could also be found in other publicly available models. The company confirmed that the capabilities demonstrated in the jailbreak report are not unique to Fable 5 and can be replicated by other models, such as OpenAI's GPT-5.5.
As a result, access to these models was disabled for all customers, while other Anthropic models remain unaffected. Further details are expected to be shared shortly.