Opus 5: Least Prompt-Injectable Model Yet, Attack Success Rate Near Zero with Layered Defenses

Anthropic highlights Opus 5's excellence in coding, data analysis, design, biology, and knowledge work, but the most exciting aspect is its prompt injection resistance. According to the system card, Opus 5 is the hardest model to prompt inject yet. When layering strong alignment, injection probes, and Auto Mode in Claude Code, the success rate drops to nearly 0%.

• Anthropic
• safety
• Claude Opus 5
• Prompt Injection Defense