A content management system (CMS) is a tool that enables users to create and manage digital properties, such as websites. CMS allows multiple team members to create, edit, and publish content while also serving as a centralized database for content storage. 

CMS frameworks have become essential components of modern web applications. 

The Advanced CMS Security Expert (ACSE) online training program equips professionals with the high-level skills required to carry out successful penetration tests against modern CMS-based web applications. This training covers the most advanced web application pentesting techniques.

Although the training is focused on the offensive approach, it provides the best exercises to tackle modern CMS-based web application security issues discovered during bug bounty hunting and penetration testing.