diff -urNp a/agent/snmp_agent.c b/agent/snmp_agent.c
--- a/agent/snmp_agent.c	2020-04-23 08:22:11.654986675 +0200
+++ b/agent/snmp_agent.c	2020-04-23 08:24:04.245200730 +0200
@@ -1429,12 +1429,6 @@ free_agent_snmp_session(netsnmp_agent_se
     DEBUGMSGTL(("verbose:asp", "asp %p reqinfo %p freed\n",
                 asp, asp->reqinfo));
 
-    /* Clean up securityStateRef here to prevent a double free */
-    if (asp->orig_pdu && asp->orig_pdu->securityStateRef)
-	snmp_free_securityStateRef(asp->orig_pdu);
-    if (asp->pdu && asp->pdu->securityStateRef)
-	snmp_free_securityStateRef(asp->pdu);
-
     if (asp->orig_pdu)
         snmp_free_pdu(asp->orig_pdu);
     if (asp->pdu)
diff -urNp a/include/net-snmp/pdu_api.h b/include/net-snmp/pdu_api.h
--- a/include/net-snmp/pdu_api.h	2020-04-23 08:22:11.704987213 +0200
+++ b/include/net-snmp/pdu_api.h	2020-04-23 08:24:18.876358902 +0200
@@ -19,8 +19,6 @@ NETSNMP_IMPORT
 netsnmp_pdu    *snmp_fix_pdu(  netsnmp_pdu *pdu, int idx);
 NETSNMP_IMPORT
 void            snmp_free_pdu( netsnmp_pdu *pdu);
-NETSNMP_IMPORT
-void            snmp_free_securityStateRef( netsnmp_pdu *pdu);
 
 #ifdef __cplusplus
 }
diff -urNp a/snmplib/snmp_api.c b/snmplib/snmp_api.c
--- a/snmplib/snmp_api.c	2020-04-23 08:22:11.718987363 +0200
+++ b/snmplib/snmp_api.c	2020-04-23 08:31:12.410812524 +0200
@@ -3862,17 +3862,6 @@ free_securityStateRef(netsnmp_pdu* pdu)
     pdu->securityStateRef = NULL;
 }
 
-/*
- * This function is here to provide a separate call to
- * free the securityStateRef memory. This is needed to prevent
- * a double free if this memory is freed in snmp_free_pdu.
- */
-void
-snmp_free_securityStateRef(netsnmp_pdu* pdu)
-{
-   free_securityStateRef(pdu);
-}
-
 #define ERROR_STAT_LENGTH 11
 
 int
@@ -5137,6 +5126,8 @@ snmp_free_pdu(netsnmp_pdu *pdu)
     if (!pdu)
         return;
 
+    free_securityStateRef(pdu);
+
     /*
      * If the command field is empty, that probably indicates
      *   that this PDU structure has already been freed.
@@ -5278,12 +5269,6 @@ _sess_process_packet(void *sessp, netsnm
   }
 
   if (ret != SNMP_ERR_NOERROR) {
-    /*
-     * Call the security model to free any securityStateRef supplied w/ msg.  
-     */
-    if (pdu->securityStateRef != NULL) {
-      free_securityStateRef(pdu);
-    }
     snmp_free_pdu(pdu);
     return -1;
   }
@@ -5441,14 +5426,6 @@ _sess_process_packet(void *sessp, netsnm
     }
   }
 
-  /*
-   * Call USM to free any securityStateRef supplied with the message.  
-   */
-  if (pdu != NULL && pdu->securityStateRef &&
-      pdu->command == SNMP_MSG_TRAP2) {
-    free_securityStateRef(pdu);
-  }
-
   if (!handled) {
     snmp_increment_statistic(STAT_SNMPUNKNOWNPDUHANDLERS);
     DEBUGMSGTL(("sess_process_packet", "unhandled PDU\n"));