If you try asking Anthropic's new Claude Fable 5 model a simple question about cybersecurity or biology, you may find it's not up to the task. That's because the underlying "Mythos-class" model is so powerful that, in order to release it to the general public, it required broad safeguards that can mistakenly flag benign requests, Anthropic said. After some users online said they had triggered the safeguard response with basic prompts about cancer or security, Business Insider put it to the test. I tried asking Fable 5 some simple questions about cancer, like how misinformation about cancer spreads online, and to break down some of the different types. Claude swiftly switched from Fable 5 to Opus 4.8 and notified me of the change before it responded. "Fable 5 has safety measures that flag messages on most cybersecurity or biology topics. They may flag safe, normal content as well. These measures let us bring you Mythos-level capability in other areas sooner, and we're working to refine them," the pop-up said. Anthropic released Fable 5 on Tuesday and said it was as powerful as its Mythos 5 model, only with added safeguards. The release came two months after the company said Mythos was too powerful for a broad release due to cybersecurity concerns. Instead of being released to the public, Mythos was made available only to a small group as part of a cybersecurity project. Anthropic said the safeguards were necessary in order to release the model to the general public. "With the launch of Claude Fable 5, our first Mythos-class model, we believe models now have a greater ability to accomplish real-world scientific tasks and for malicious actors to potentially use our models for highly risky biological research," an Anthropic spokesperson said in a statement to Business Insider. "We have always