Anthropic shuts down Fable, Mythos brands following Trump admin directives

Anthropic completely shut down access to its Mythos 5 and Fable 5 versions on Friday night, just days after they launched.

The move comes after Anthropic received guidance from the US Department of Commerce on Friday evening, subjecting the new brands to export regulations that prohibit any use outside of the United States. In message that was sent on Friday nightAnthropic said the only way to ensure compliance with the government’s order soon “is that we must immediately cancel Fable 5 and Mythos 5 for all our customers.” Finding other Anthropic species is not affected.

An Axios report A government official mentioned that the authorities have been affected by the reports of the alleged prison break multi-level security meaning to stop what Fable 5 is introducing related to cybersecurity, chemistry, and biology. Officials are said to have requested a pause in the release of these models to allow time for “national security tools” to be “hardened” against this type of threat. The freeze could end “in the next few weeks,” Axios’ source said.

In its announcement Friday night, Anthropic said the government had only provided “verbal evidence of a narrow, non-global jailbreak” that included access to Fable 5 to review its codebase for software flaws. The company says that it has only seen evidence of this version being used to find “minor” and “easy” software vulnerabilities, and that other publicly available versions like GPT-5.5 have similar capabilities to this list.