As of SERVER-14089 (MongoDB 2.7.2), the auth schema version must be authSchemaVersion26 (3).  Mongos and mongod should check early in execution that this is so, and log a message and terminate if it is not.
This ticket should also include writing a multiVersion test to ensure this behavior.
- is related to
- 
                    SERVER-14089 Remove support for v2.4 schema users -         
- Closed
 
-