AISI says open-weight AI cyber capability gap has narrowed to 4-7 months
The UK AI Security Institute said in a July 17 report that leading open-weight AI models are now 4 to 7 months behind frontier closed models in cyberattack capability, narrowing from a 6 to 10 month gap seen in internal testing last year. The institute used two evaluation systems: a 70-task benchmark covering vulnerability research, reverse engineering, web exploitation and cryptography, and a Cyber Range environment designed to test multi-step autonomous attack chains in a simulated enterprise network. Across those tests, GLM-5.2 matched Opus 4.6 on narrow tasks with a four-month lag, and reached Opus 4.5-level performance on Cyber Range with a seven-month lag, while DeepSeek V4-Pro tracked Opus 4.5 on narrow tasks with a five-month gap. The report also found a much wider pricing gap than the capability gap. In a Cyber Range run with a 100 million token budget, Opus 4.5 or 4.6 cost about $85, GLM-5.2 about $46, and DeepSeek V4-Pro $1.19. AISI said the shrinking lead time leaves defenders with less preparation time and sharpens a policy question now moving to the center: above what capability level should model weights no longer be openly released?







