Jenkins Subversion Partial Release Manager Plugin 1.0.1 and earlier programmatically disables the fix for CVE-2016-3721 whenever a build is triggered from a release tag, by setting the Java system property 'hudson.model.ParametersAction.keepUndefinedParameters'.
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.