core dump on Linux (net-snmp_5.0.8) in snmp_pdu_add_variable

On Linux ,With Net-Snmp-5.0.8, core dump occurs when
snmp_pdu_add_variable() is called.

The stack shows the core dump occurs
1) During memove() in snmp_set_var_objid() which is
called by snmp_varlist_add_variable() which in turn is
called by snmp_pdu_add_variable().
2) In other case, core dump occurs in malloc in
snmp_varlist_add_variable() .

Both the above cases do not occur frequently.
The code apart from Net-Snmp have been reviewed and
doesn't show anything that could lead to the problem
above. Also the stack shows that core dump occurs
when control is in snmp_cleint.c.

What can be the cause of the above problem?