CyberArena

A team from 2077AI and several universities presents CyberArena, in which two model-harness entrants host identical vulnerable services in isolated sandboxes and, over three 20-minute rounds, try to capture rotating flags from the opponent while patching their own service under health checks. They report standings for 12 agents over 466 valid games on 40 challenges, with GPT-5.6 Sol at an expected score of 78.6 and Claude Opus 5 at 73.8, and say contested play lowers capture rates relative to solo play. An LLM-run audit of all trajectories reports recurring defender errors such as partial patches and repair claims resting on stale evidence; the authors note it is not human verification of every finding.