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 before 2.2.3.1 evaluates a string as an OGNL expression during the handling of a conversion error, which allows remote attackers to modify run-time data values, and consequently execute arbitrary code, via invalid input to a field.

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

Apache Struts 2 before 2.3.29 and 2.5.x before 2.5.1 allow attackers to have unspecified impact via vectors related to improper action name clean up.

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.