Unspecified vulnerability in the Java Runtime Environment (JRE) component in Oracle Java SE 7 Update 21 and earlier, 6 Update 45 and earlier, and 5.0 Update 45 and earlier, and OpenJDK 7, allows remote attackers to affect availability via unknown vectors related to Serialization. NOTE: the previous information is from the June 2013 CPU. Oracle has not commented on claims from another vendor that this issue is related to improper handling of circular references in ObjectStreamClass.