WP Meta SEO <= 4.5.3 - Cross-Site Request Forgery via 'regenerateSitemaps'

The WP Meta SEO plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 4.5.3. This is due to missing or incorrect nonce validation on the regenerateSitemaps function. This makes it possible for unauthenticated attackers to regenerate Sitemaps via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.