Two bug could be related to this error Bug 6085625 and unpublished bug 6452485.
to fix the above bug you need to apply Patch 6602742 or Patch 6602482 Depend on your case
as workaround you have to optiosn :
A. Flushing the shared pool can help remove the problem cursor from the shared pool.
B. Or set SESSION_CACHED_CURSORS = 0
Thank you
Osama mustafa
Technology Geek 