All benchmarks

ExploitBench (Cap%)

Cybersecurity

ExploitBench measures offensive cybersecurity capability: discovering and exploiting software vulnerabilities end to end. Scores are the capability percentage (Cap%) achieved across the exploit suite. Frontier scores here are why Mythos-class access is gated.

Model scores

  • Fable 578.0%
  • Opus 4.840.0%
  • Sonnet 5
  • GPT-5.6 Sol73.5%
  • GPT-5.547.9%
  • Composer 2.5
  • Opus 4.7
  • Gemini 3.1 Pro
  • Mythos Preview69.0%

Official source: Anthropic — Fable 5 / Mythos 5 announcement

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