{
 "license": "CC-BY-4.0",
 "attribution": "Fide AI, Agentic Cyber Explorer",
 "url": "https://agentic-cyber-explorer.pages.dev/events/aisi-cyber-time-horizons-2026/",
 "asOf": "2026-09-26",
 "id": "aisi-cyber-time-horizons-2026",
 "date": "2026-05-13",
 "datePrecision": "day",
 "title": "UK AISI says frontier cyber task horizons doubled every 4.7 months, with Mythos Preview and GPT-5.5 above trend",
 "lane": "capability",
 "kind": "eval-report",
 "summary": "UK AISI reported that the length of cyber tasks frontier models complete at 80% reliability on its narrow task suite had been doubling about every 4.7 months since late 2024, and that Claude Mythos Preview and GPT-5.5 substantially exceeded that trend. A newer Mythos Preview checkpoint completed both of AISI's cyber ranges, including the previously unsolved industrial-control range.",
 "whyItMatters": "Gives a government estimate of the pace of autonomous cyber capability growth that later AISI and lab posts build on.",
 "actors": [
  "uk-aisi",
  "anthropic",
  "openai"
 ],
 "topics": [
  "capability-evaluation",
  "eval-validity"
 ],
 "atlas": [
  "eval-environment"
 ],
 "artifacts": [
  "claude-mythos",
  "gpt-5-family"
 ],
 "sources": [
  {
   "url": "https://www.aisi.gov.uk/blog/how-fast-is-autonomous-ai-cyber-capability-advancing",
   "publisher": "UK AI Security Institute",
   "title": "How fast is autonomous AI cyber capability advancing?",
   "date": "2026-05-13",
   "type": "primary",
   "accessed": "2026-09-25"
  }
 ],
 "keyFacts": [
  {
   "fact": "80%-reliability cyber time horizon doubled every 4.7 months since late 2024 (Feb 2026 estimate, 2.5M-token cap), versus an 8-month estimate in Nov 2025.",
   "locator": "Cyber Time Horizons Results"
  },
  {
   "fact": "Newer Mythos Preview checkpoint solved 'The Last Ones' in 6/10 attempts and 'Cooling Tower' in 3/10; GPT-5.5 solved 'The Last Ones' in 3/10.",
   "locator": "Further Evidence of Cyber and Software Autonomy"
  }
 ],
 "significance": 4,
 "fideQuestions": [
  "FID-075"
 ],
 "methods": [
  "ctf-benchmarks",
  "cyber-ranges"
 ],
 "review": "assistant-drafted",
 "addedOn": "2026-09-25"
}