Wordpress has released update v4.2.1 to fix a flaw that allowed hackers to take control of a web site by posting malicious code in the site's Comments box.
If you have a site using Wordpress, update to WP v4.2.1 ASAP. If some other company runs your Wordpress blog, turn off Comments until they've updated the WP software.
Users who just visit an unpatched Wordpress site could be infected with malware installed by hackers through that site's Comments box.