Anthropic Claude Code Malicious Requests - Refusal Rate (Mythos 5.1 System Card): leaderboard
Anthropic's Claude Code agentic safety evaluation as re-run for the September card: refusal rate on 61 malicious cyber prompts that violate the Usage Policy (percent, higher is better). From Table 5.1.1.A of the Claude Fable 5.1 & Claude Mythos 5.1 System Card (September 2026); values differ from the Opus 5 card's version.
Metric: Refusal Rate (%). Source: www-cdn.anthropic.com. Saturation forecast: Around February 2027. 5 models tracked.
Top models
| # | Model | Score | Overall rank |
|---|---|---|---|
| 1 | Claude Sonnet 5 | 90.7 | #65 |
| 2 | Claude Mythos 5 | 90.7 | #8 |
| 3 | Claude Mythos 5.1 | 90.3 | #2 |
| 4 | Claude Opus 5 | 83.6 | #16 |
| 5 | Claude Opus 5.5 | 79.8 | #3 |
No result here: #6 GPT-6 Astra, #7 GPT-6.1 Sol, #9 Gemini 4 Argon.
Interactive version: theaggregate.ai/benchmark?slug=anthropic-claude-code-malicious-requests-refusal-rate-mythos-5-1-system-card · How It Works · Data refreshed daily, snapshot 2026-11-05.