What potential security risks should be considered when storing data in PHP sessions?

One potential security risk when storing data in PHP sessions is the possibility of session hijacking, where an attacker gains unauthorized access to a user's session data. To mitigate this risk, it is important to regenerate the session ID after a user logs in or performs a privileged action. This helps prevent session fixation attacks and ensures that each user has a unique session ID.

// Regenerate session ID after login or privileged action
session_regenerate_id(true);