Apprentice-level cyber task success: 9%
Late 2023
HCAST: 70 to 80% success on tasks taking skilled humans under one hour
Mar 2025
CyberGym: about 20% success on vulnerability reproduction tasks
Jun 2025
First expert-level (10+ years experience) cyber task completions
2025
Frontier Safety Framework defines tracked cyber capability levels
Sep 2025
Apprentice-level cyber task success: 50%
Late 2025
Mythos Preview: first model to complete The Last Ones, 3 of 10 attempts
Apr 2026
GPT-5.5 completed The Last Ones in 2 of 10 attempts
Apr 2026
Newer Mythos Preview checkpoint: The Last Ones 6 of 10
May 2026
First ever completion of the Cooling Tower ICS range: 3 of 10
May 2026
Lab system card reported a broader cyber evaluation suite
Jul 2026
Lab system card treated the model as High cyber capability under its framework
2026 system card
Artificial Analysis Cyber Index leaders scored 56
Sep 2026
Taiwan government confirms hybrid AI-agent campaign reporting
13 Aug 2026 · corroborated · high confidence
AI-orchestrated espionage campaign reported by Anthropic
13 Nov 2025 · self reported · medium confidence