Missing XML Validation vulnerability in Apache Struts, Apache Struts. This issue affects Apache Struts: from 2.0.0 before 2.2.1; Apache Struts: from 2.2.1 through 6.1.0. Users are recommended to upgrade to version 6.1.1, which fixes the issue.Referenceshttps://cwiki.apache.org/confluence/display/WW/S2-069