The Social Media Share Buttons & Social Sharing Icons WordPress plugin before 3.0.1 does not properly escape a value taken from the incoming request before outputting it in an inline JavaScript event handler, leading to Reflected Cross-Site Scripting which is triggered when a user interacts with the affected button.
Exploitation requires the Social Media Share Buttons & Social Sharing Icons WordPress plugin before 3.0.1 to be running a non-default icon display configuration.