On July 1, 2026, Anthropic announced the redeployment of Claude Fable 5 and Claude Mythos 5 after the US government lifted export controls that had been applied on June 12. The controls had forced Anthropic to restrict access to foreign nationals and ultimately suspend both models for all users.
Fable 5 is now available globally on the Claude Platform, Claude.ai, Claude Code, and Claude Cowork. Pro, Max, Team, and select Enterprise plan users will have Fable 5 included for up to 50% of weekly usage limits through July 7, after which it will be available via usage credits. Access on AWS, Google Cloud, and Microsoft Foundry is being restored as quickly as possible. Mythos 5 has been restored for a set of US organizations following government approval on June 26, with broader access for Glasswing partners still under coordination.
The export controls were triggered by a report from Amazon researchers who found a method to bypass Fable 5’s safeguards, prompting it to identify software vulnerabilities and, in one case, produce exploit code. Anthropic’s testing showed that many less capable models could also identify the same vulnerabilities and produce the same exploit demonstration, indicating the behavior was not unique to Fable 5 or indicative of Mythos-level capabilities.
To address the reported bypass, Anthropic trained an improved safety classifier that blocks the specific technique in over 99% of cases. The classifier also flags benign requests more often, but Anthropic plans to refine it to reduce false positives. Researchers from the US Department of Commerce’s Center for AI Standards and Innovation (CAISI) have validated the strength of the new safeguards.
Anthropic also outlined a shared industry framework for assessing and fixing jailbreaks, developed with Amazon, Microsoft, Google, and other Glasswing partners. The framework aims to standardize severity judgments, help triage findings, and improve communication with government and industry. Additionally, Anthropic is deepening collaboration with the US government on pre-release testing, information sharing, and research.