Statement on the US government directive to suspend access to Fable 5 and Mythos 5
Simon Willison · Simon Willison · 2026-06-13
Simon Willison reports on a US government export control directive ordering Anthropic to suspend Fable 5 and Mythos 5 access for all foreign nationals based on a claimed jailbreak, while noting Anthropic contests the severity of the finding and Willison still had personal access at time of writing.
Appears in
Extraction
Topics: ai-regulationexport-controlsgovernment-ai-policyanthropic-fablejailbreaking
Claims
- The US government issued an export control directive requiring Anthropic to suspend all foreign national access to Fable 5 and Mythos 5, citing national security concerns about a jailbreak.
- Anthropic's review of the demonstrated vulnerability found it was minor and replicable with other publicly available models including GPT-5.5.
- Simon Willison still had personal access to Fable via Claude.ai and Claude Code at 9:01pm ET despite the directive being issued.
Key quotes
Well this is nuts
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.
We have reviewed the report and validated that the level of capability displayed there is widely available from other models (including OpenAI's GPT-5.5), and is used every day by the defenders who keep systems safe.