It was discovered that the RMI (Java Remote Method Invocation) server implementation in the JMX (Java Management Extensions) component of OpenJDK did not restrict which classes can be deserialized when deserializing authentication credentials. A remote unauthenticated attacker able to connect to a JMX port could possibly use this flaw trigger deserialization flaws.
An unspecified flaw was found in the Libraries component in OpenJDK. ObjectInputStream's readSerialData() could, in certain cases, incorrectly perform deserialization of data from serialized input. An untrusted Java application or applet could use this flaw to bypass Java sandbox restrictions.