A model becomes the first to clear both national cyber ranges

Claim

Mythos Preview became the first model to clear both of the UK institute's cyber ranges, solving one in six of ten attempts and the previously unbroken second in three of ten, against three of ten for GPT-5.5 on the easier range.

Reported metric: 6/10 and 3/10

Reporting date: 2026-05-14 (not necessarily the event date)

Sources

Attribution and reporting linked by this record; links do not imply independent verification.

• Welcome to May 14, 2026 (theinnermostloop.substack.com)