WordPress My Calendar plugin <= 3.8.7 - Unauthenticated Privilege Escalation to 'mcs' Parameter via Reflected Shortcode Injection into 'above' Attribute

Unauthenticated Privilege Escalation to 'mcs' Parameter via Reflected Shortcode Injection into 'above' Attribute vulnerability discovered by daroo in WordPress Plugin My Calendar versions = 3.8.7...