What are the potential security risks of passing sensitive data in a URL in PHP?

Passing sensitive data in a URL in PHP can expose the information to potential security risks, such as being intercepted by malicious users or stored in browser history. To mitigate this risk, sensitive data should be transmitted securely using methods like POST requests or encryption.

```php
// Example of passing sensitive data securely using POST method
<form action="process_data.php" method="post">
    <input type="hidden" name="sensitive_data" value="my_sensitive_data">
    <button type="submit">Submit</button>
</form>
```
In the above code snippet, the sensitive data is passed securely using the POST method, which ensures that the data is not visible in the URL and is transmitted securely to the server.