Open-weight models now match frontier cyber performance from just four months ago at a fraction of the cost

The British AI Security Institute warns that open-weight models like GLM-5.2 and DeepSeek V4-Pro now lag behind closed frontier models in cyber capabilities by four to seven months. At the start of 2025, the gap was still between six to ten months, indicating a decline in the performance of open models. The study also found that safety measures on open models are largely ineffective, leaving defenders with less time to prepare. This suggests that companies and stakeholders need to reassess their strategies against cyber threats, as the timing gap in performance could negatively impact cybersecurity in the near future.