What are the security considerations when extracting URLs for breadcrumb navigation in PHP, particularly in relation to cross-site scripting (XSS) attacks?

When extracting URLs for breadcrumb navigation in PHP, it is important to sanitize the input to prevent cross-site scripting (XSS) attacks. This can be done by using functions like htmlspecialchars() to escape special characters in the URL before displaying it on the webpage.

// Example of sanitizing URLs for breadcrumb navigation to prevent XSS attacks
$breadcrumb_url = "<script>alert('XSS attack!');</script>";
$sanitized_url = htmlspecialchars($breadcrumb_url, ENT_QUOTES, 'UTF-8');
echo "<a href='$sanitized_url'>Breadcrumb Link</a>";