What are some potential pitfalls to be aware of when using popovers in PHP?

One potential pitfall when using popovers in PHP is the risk of XSS (Cross-Site Scripting) attacks if user input is not properly sanitized before being displayed in the popover. To prevent this, always make sure to escape user input using htmlspecialchars() function before outputting it in the popover.

// Sanitize user input before displaying in popover
$user_input = "<script>alert('XSS attack!')</script>";
$escaped_input = htmlspecialchars($user_input);
echo "<div class='popover'>$escaped_input</div>";