What are common security risks associated with PHP sessions and how can they be mitigated?

One common security risk associated with PHP sessions is session hijacking, where an attacker steals a user's session ID and impersonates them. This can be mitigated by using session_regenerate_id() to generate a new session ID after a successful login, making it harder for attackers to hijack sessions.

// Generate a new session ID after successful login
session_start();
session_regenerate_id(true);