Cybersecurity researchers aren't happy about the guardrails on Anthropic's Fable

Anthropic released Fable, a limited version of its cybersecurity model Mythos, with guardrails that block even innocuous cybersecurity-related requests. Researchers like Valentina Palmiotti and Matt Suiche criticized the keyword-based restrictions, which cause Fable to fall back to Claude Opus 4.8 when triggered.