What are the best practices for validating user input to prevent injection attacks in message-based systems

Question

To secure a messaging system, I’m focused on validating user input to prevent injection attacks. I know input validation can reduce risks from SQL, XSS, and other types of injections, but I’d like to understand the best practices for this in the context of a messaging platform.

Are there specific validation rules or libraries that are particularly effective for message data? Any insights into filtering techniques or sanitation best practices would be useful.