What are the potential security risks of sharing session variables between different websites in PHP?

Sharing session variables between different websites in PHP can pose a significant security risk as it can lead to session hijacking or data leakage. To mitigate this risk, it is recommended to use separate session identifiers for each website to ensure that sessions are isolated and not accessible across different domains.

// Set a unique session name for each website
session_name("website1_session");
session_start();

// Your website1 code here
```

```php
// Set a unique session name for each website
session_name("website2_session");
session_start();

// Your website2 code here