We need to summarize the news in 3-4 sentences, max 400 characters. Must be factual, no evaluation. Let’s extract key facts:
- US authorities lifted export restrictions on Claude Fable 5 and Mythos 5.
- Fable 5 is now globally available via Claude.ai, Platform, Code, Cowork; access restored July 1 2026 (future date) and will be on AWS, Google Cloud, Microsoft Foundry.
- Mythos 5 is available to a limited number of US companies and government entities since June 26.
- The ban was imposed June 12 by US Commerce Department due to security concerns; developers disabled both models shortly after launch.
- Researchers at Amazon found a jailbreak that bypassed Fable 5 protection, enabling it to reveal vulnerabilities and generate PoC code; similar issues found in Claude Opus 4.8, GPT-5.5, Kimi K2.7.
- Anthropic enhanced Fable 5 protection, now blocks jailbreak in >99% of cases, but causes more false positives for programming requests.
- Mythos 5 remains less restricted and can more effectively find/exploit vulnerabilities, so access stays limited.
- Anthropic created a 24/7 team to monitor jailbreak reports, launched a bug bounty on HackerOne, and is developing a joint danger assessment system with Amazon, Microsoft, Google, etc., using four criteria.
Now need 3-4 sentences, under 400 characters. Let’s craft 3 sentences.
Sentence 1: US authorities lifted export bans on Claude Fable 5 and Mythos 5, restoring global access to Fable 5 via Claude services and planning its return to AWS, Google Cloud and Microsoft Foundry, while Mythos 5 remains limited to selected US entities. (That’s long; maybe split.)
We need 3-4 sentences total.