After installing the ArcGIS Oracle Critical Patch Update - October 2014 patch, ArcMap crashes, usually when editing and typically with no warning. No relevant errors are seen in the log files.
After applying the Esri patch, ArcGIS looks for an OPEN_CURSORS entry in SDE.SERVER_CONFIG. If not found, ArcGIS assumes a default value of 300.
Check SDE's server_config OPEN_CURSORS parameter. The value should match the value of OPEN_CURSORS in Oracle. Use the follow information to add the parameter to sde.server_config:
SQL> insert into sde.server_config (prop_name,char_prop_value,num_prop_value)
The above example sets the OPEN_CURSORS parameter to 4000.
Esri is currently investigating this issue.