SPFx: Be prepared for the Content Security Policy (CSP) in SharePoint Online
Very soon in March 2026, the new Content Security Policy will be switched from report-only mode to active blocking (enforcement) mode. If you are not prepared, maybe some custom web parts or extensions will stop working. If the term "SharePoint Online Content Security Policy (CSP)" is new for you, you should continue reading. If you are already prepared, keep relaxed😎. SharePoint Online Content Security Policy (CSP) - explained Regarding the Microsoft SharePoint Blog post CSP means: Content Security Policy (CSP) is a critical browser security feature designed to protect web applications from threats like cross-site scripting (XSS), clickjacking, and other code injection attacks. CSP allows site owners to specify which resources (scripts, styles, images, etc.) a page can load, reducing the risk of malicious code execution. More about CSP: Content Security Policy (CSP) The basic facts about CSP are: strengthen SharePoint Online security by only allowing to load approv...