Memory leak in mongo-java-driver v 2.12.0

Question

Env:

Java: 1.8

Mongo db: 2.6.7

Mongo-java driver: 2.12.0

Apache-Tomcat: 7.0.53

Error

I get these errors when I am closing the connections in mongo cursor. These are potential memory leaks.

Log

java.lang.IllegalStateException: open
        at org.bson.util.Assertions.isTrue(Assertions.java:36) ~[mongo-java-driver-2.12.0.jar:na]
        at com.mongodb.DBTCPConnector.isMongosConnection(DBTCPConnector.java:374) ~[mongo-java-driver-2.12.0.jar:na]
        at com.mongodb.Mongo.isMongosConnection(Mongo.java:645) ~[mongo-java-driver-2.12.0.jar:na]
        at com.mongodb.DBCursor._check(DBCursor.java:454) ~[mongo-java-driver-2.12.0.jar:na]
        at com.mongodb.DBCursor._hasNext(DBCursor.java:546) ~[mongo-java-driver-2.12.0.jar:na]
        at com.mongodb.DBCursor.hasNext(DBCursor.java:571) ~[mongo-java-driver-2.12.0.jar:na]
.......

Any fix available?