The getTip() method of Action Columns of Sencha Ext JS 4 to 6 before 6.6.0 is vulnerable to XSS attacks, even when passed HTML-escaped data. This framework brings no built-in XSS protection, so the developer has to ensure that data is correctly sanitized. However, the getTip() method of Action Columns takes HTML-escaped data and un-escapes it. If the tooltip contains user-controlled data, an attacker could exploit this to create a cross-site scripting attack, even when developers took precautions and escaped data.