Anthropic Disables Claude Fable 5 and Mythos 5 After US Government Export Control Order on June 12, 2026
English summary
On June 12, 2026, a US export control directive forced Anthropic to disable its two most capable models, Claude Fable 5 and Mythos 5, for all users because it could not filter foreign nationals in real time. The order followed a claim by another company that it had jailbroken Mythos, but Anthropic disputes this as a narrow, non-universal jailbreak. Fable 5's safety system uses classifiers that route risky queries (cybersecurity, bio-chem, distillation) to Opus 4.8 in under 5% of sessions; the model had been publicly available since June 9. All other Claude models, including Opus 4.8, remain unaffected. This appears to be the first government-forced takedown of a publicly deployed frontier AI model.
Chinese summary
2026年6月12日，美国商务部出口管制指令迫使Anthropic对其所有用户关闭两款最强模型Claude Fable 5和Mythos 5，原因是无法实时过滤外籍人士访问。该命令源于另一家公司声称已破解Mythos模型的安全限制，但Anthropic辩称该破解范围狭窄且非通用。Fable 5的安全系统通过分类器将网络安全、生化及知识蒸馏等敏感查询回退至Opus 4.8，触发率低于5%的会话；该模型自6月9日起公开提供服务。其他Claude模型（包括Opus 4.8）未受影响。这似乎是首例政府强制下架公开部署的前沿AI模型的事件。
Key points
A US export control directive on June 12, 2026, forced Anthropic to disable Claude Fable 5 and Mythos 5 for all users, as it could not filter foreign nationals in real time.
2026年6月12日，美国出口管制指令迫使Anthropic关闭所有用户的Claude Fable 5和Mythos 5，因其无法实时过滤外籍人士访问。
The shutdown was triggered by another company's claim of a jailbreak on Mythos; Anthropic argues the jailbreak is narrow and non-universal, and the approach is comparable to capabilities in other public models.
关闭起因是另一家公司声称破解了Mythos安全措施；Anthropic辩称该破解窄而不具普遍性，且其能力与其他公开模型相当。
Fable 5's safeguards included classifiers that route risky queries to Opus 4.8 in under 5% of sessions; over 95% of sessions experienced no fallback.
Fable 5的安全防护包含分类器，在不足5%的会话中将风险查询回退至Opus 4.8；超过95%的会话无需回退。
All other Anthropic models, including Claude Opus 4.8, remain unaffected and available.
包括Claude Opus 4.8在内的其他所有Anthropic模型均未受影响，仍可使用。
This is reportedly the first instance of a government-forced takedown of a publicly deployed frontier AI model, with implications for AI deployment and export controls.
这是首次政府强制下架公开部署的前沿AI模型的事件，对AI部署与出口管制具有深远影响。