ORA-00700: soft internal error, arguments: [kesqsMakeSql-invstat:cpuTime], , , , , , , [
] ... hmmm ... it looks impressive, overall considering that an ORA-00600 is not one that probably is going to make your DBA day.
Actually it is not as tragic and epic as it could seem to be at first glance, it has to do with a bug. In this particular case it showed up in an Oracle 11g Rel.1 (126.96.36.199.0) version on a x64 windows platform. This error is triggered when the SYS_AUTO_SQL_TUNING_TASK runs, and it may spontaneously show up and keep on showing up for a while. It may happen to be annoying.
The root reason is the Bug 7025700 , and some other related bugs, Bug 7757533, Bug 8224438, Bug 7643188, the arguments of the ORA-00700 may be slightly different: [KESQSMAKESQL-INVSTAT:CPUTIME], or [KESQSMAKESQL-INVSTAT:ELPSTIME], and the solution is to apply the patch 7643188 or apply the PSU patch to upgrade to 188.8.131.52.2.
Applying the patch will fix the problem from occurring in the future, but it won't fix the current corrupted data at the internal statistics tables, but eventually those corrupt rows will be flushed away, so in the mean time you'll have jut to get used to acknowledge it and manually clear the errrors at your E.M. Console.