Unspecified vulnerability in the MySQL Server component in Oracle MySQL 5.6.12 and earlier allows remote authenticated users to affect availability via unknown vectors related to Optimizer.
http://www.securitytracker.com/id/1029184
http://www.securityfocus.com/bid/63113
http://www.oracle.com/technetwork/topics/security/cpuoct2013-1899837.html