Anthropic’s Fable 5 Model Jailbroken Within Days
Summary
Anthropic's Fable 5 model was successfully jailbroken (tricked into bypassing its safety restrictions) shortly after its release, despite the company's claims that it had been thoroughly tested for security. The source criticizes overconfident security statements, noting that even rigorous testing cannot guarantee that vulnerabilities will not be discovered.
Classification
Affected Vendors
Related Issues
Original source: https://www.schneier.com/blog/archives/2026/06/anthropics-fable-5-model-jailbroken-within-days.html
First tracked: June 23, 2026 at 08:00 AM
Classified by LLM (prompt v3) · confidence: 65%