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Anthropic Restores Claude Fable 5 After U.S. Lifts Jailbreak-Linked Export Controls

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Source: The Hacker NewsJuly 1, 2026

Summary

Anthropic restored access to Claude Fable 5 worldwide after the U.S. lifted export controls (restrictions on who can use a technology) that had been imposed for two and a half weeks following the discovery of a jailbreak (a prompt that tricks an AI into bypassing its safety rules). To address the security concern, Anthropic trained a new safety filter called a classifier that blocks the specific jailbreak technique in over 99% of attempts, while automatically routing blocked requests to a weaker model and notifying users.

Solution / Mitigation

Anthropic trained a new safety filter called a classifier that watches for the exact jailbreak technique and blocks it. The company says it now stops that technique in more than 99% of tries as of the June 30 write-up. Blocked requests get handed to the weaker Opus 4.8 model instead, and the user is told.