Findings/cyber-time-horizons-doubling

Under a 2.5M-token cap, frontier cyber task time horizons doubled on the order of months between late 2024 and early 2026.

Qualifiedmeasured1 evidence record from 1 independent sourceassistant-drafted

Scope: what this does not show

One evaluator's task suite at a fixed budget.

Qualified: Still standing, but later work narrows how far it applies.

Evidence

May 13, 2026

UK AISI says frontier cyber task horizons doubled every 4.7 months, with Mythos Preview and GPT-5.5 above trend

UK AI Security Institute

How it relates to other findings

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Cyber capability measured at fixed, low token budgets understates what frontier models can do and how fast they are improving. qualifies this findingThe doubling estimate was measured at a fixed low budget.

Status history

2026-05-13ReportedUK AISI estimates cyber time-horizon doubling. · record
2026-07-02QualifiedUK AISI later shows fixed budgets understate capability, so the trend is a lower bound. · record

What would change this: A remeasurement with scaled budgets and cheating controls.
Evidence kind: measured: An experiment or evaluation produced the number.
Freshness: Evidence 86d old · recheck in 154 daysNewest evidence Jul 2, 2026. Half-life 240 days.
Methods tested: Compute-scaled evaluation CTF and task benchmarks
Topics: Capability evaluation
Fide research: FID-075: Cybersecurity capabilities and whole-system risk

Cite this record

Fide AI. "Under a 2.5M-token cap, frontier cyber task time horizons doubled on the order of months between late 2024 and early 2026.." Agentic Cyber Explorer, record cyber-time-horizons-doubling. https://agentic-cyber-explorer.pages.dev/findings/cyber-time-horizons-doubling/ (corpus as of 2026-09-26).

BibTeX

@misc{fide-ace-cyber-time-horizons-doubling,
  author = {{Fide AI}},
  title = {Under a 2.5M-token cap, frontier cyber task time horizons doubled on the order of months between late 2024 and early 2026.},
  howpublished = {Agentic Cyber Explorer},
  year = {2026},
  url = {https://agentic-cyber-explorer.pages.dev/findings/cyber-time-horizons-doubling/},
  note = {Record cyber-time-horizons-doubling; corpus as of 2026-09-26}
}

Data: JSON · CC BY 4.0

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