https://bugzilla.redhat.com/show_bug.cgi?id=243536

--- net-snmp-5.4/agent/mibgroup/agent/extend.c.orig	2006-10-18 21:07:35.000000000 +0200
+++ net-snmp-5.4/agent/mibgroup/agent/extend.c	2007-06-27 14:30:08.000000000 +0200
@@ -448,6 +448,9 @@
         extension->command  = strdup( exec_command );
         if (cptr)
             extension->args = strdup( cptr );
+    } else {
+    	snmp_log(LOG_ERR, "Duplicate MIBOID '%s' detected in exec statement, only the first one will be used.\n", exec_name);
+    	return;
     }
 
 #ifndef USING_UCD_SNMP_EXTENSIBLE_MODULE