The fix enforces the management interfaces (read MBean and MXBean interfaces) being public. While this is defined in the specification it was not enforced in any way and it was allowed to create MBeans for eg. private MBean interfaces.
The fix adds checks when creating and registering MBeans and throws javax.management.NotCompliantMBeanException when a user tries to create an MBean with non-public management interface. Since this change can cause problems for users having non-public management interfaces a system property is introduced that will revert to the old behaviour when set (com.sun.jmx.mbeans.allowNonPublic). Thanks, -JB-
