Anthropic's Fable is so safe it can't read security blogs
anthropic's new fable model blocks even innocuous security tasks like code reviews to prevent malware, frustrating researchers who say the guardrails are too aggressive.
anthropic launched fable, a limited public variant of its mythos cybersecurity model, featuring aggressive guardrails that block any input tangentially related to cybersecurity or biology. researchers, including ibm's valentina palmiotti, note the model refuses innocuous requests like code reviews or reading blogs, often defaulting to the less capable claude opus 4.8 as a fallback. the restrictions are designed to prevent the development of malware and biological weapons, addressing Anthropic's core safety concerns. however, the broad, keyword-based filtering frustrates cybersecurity professionals who cannot use the tool for defensive engineering, highlighting the difficulty in balancing open safety against utility for legitimate researchers.