For the second time, MITRE's Common Weakness Enumeration project has released a Top-25 list. However, this year's is a much more sophisticated document, created using a systematic and more rigorous approach. It contains several sections and tables as well as profiles, and isn't only a list. I will explain what the CWE is, what the purpose of the Top-25 is, how it was created, which problems it faced and which it still faces, how it has been improved since last year, and how you can use it.