Google has been known to scan WordPress sites for certain information, namely the WordPress Generator tag. This generator tag tells Google information about your WordPress install, including if it is the latest version or not.
Google Webmaster tools has since updated their software to notify users that have outdated versions of WordPress. Google Webmaster Tools has always been a place to find out if you have something wrong with your site that could be affecting your rankings. Could this mean that Google could be penalizing sites with old versions of WordPress?
Google has started sending out the following emails to websites that are running old WordPress versions:
Dear site owner or webmaster of [Site URL],
Your site appears to be running an older version of WordPress. Google recommends that you update to the latest release. Older or unpatched software may be vulnerable to hacking or malware that can hurt your users. To download the latest release, visit the WordPress download page.
If you have any additional questions about why you are receiving this message, Google has provided more background information in a blog post about this subject.
Google Search Quality Team
This would make a lot of sense in the search engine’s eyes. Websites with old version of WordPress are substantially more susceptible to WordPress attacks, which are known to redirect users, hide spam backlinks, and install malicious software on visitors computers. Does Google really want to rank a website on top of it’s search engines if it has neglected to keep it’s software updated? Google has always been about user experience, and if a site seems unstable, or if it could put it’s visitors at risk in the near future, discounting websites that are on old versions of WordPress suddenly makes perfect sense.
Jake at LockerGnome claims that hiding your WordPress generator tag can help avoid any potential penalties, or at least prolong them. There is obviously more than one benefit to having an updated version of WordPress, but this will keep Google from sending you warning messages, and possibly hurting your rankings. Simply add this line to your themes function.php file: