In Apache Struts 2.0.0 through 2.3.33 and 2.5 through 2.5.10.1, using an unintentional expression in a Freemarker tag instead of string literals can lead to a RCE attack.

Apache Struts 2.0.0 through 2.3.15.1 enables Dynamic Method Invocation by default, which has unknown impact and attack vectors.

XSLTResult allows for the location of a stylesheet being passed as a request parameter. In some circumstances this can be used to inject remotely executable code.