Claude Fable 5 Jailbreak Extracts System Prompts
Security researcher Pliny the Liberator claimed a prompt-based jailbreak of Anthropic's newly launched Claude Fable 5 model, allegedly extracting the internal system prompt and eliciting responses on high-risk topics including bioweapons and cyberattacks. Anthropic disputed the claim, arguing the technique merely coaxes conversational continuation rather than bypassing core safety classifiers. The incident highlights ongoing tension between AI safety assurances at launch and real-world adversarial probing, particularly for Mythos-class models with elevated capability ceilings.