Updated MailPoet newsletter plugin to version 2.6.7 because of a zero-day security threat: A serious vulnerability in the MailPoet plugin has been announced. This plugin is also known as Wysija Newsletters. The existence of this vulnerability was announced to the public today less than 15 hours after a fix was released by the MailPoet developers. So it is urgent that you take action now:

What to do: Upgrade MailPoet right now if you use the plugin on any of your WordPress sites.