diff -urNp e/snmplib/snmp_api.c f/snmplib/snmp_api.c
--- e/snmplib/snmp_api.c	2019-04-17 15:16:22.664807192 +0200
+++ f/snmplib/snmp_api.c	2019-04-17 15:18:09.162767964 +0200
@@ -5362,13 +5362,17 @@ _sess_process_packet(void *sessp, netsnm
 	      break;
 	    } else {
 	      /* We're done with retries, so no longer waiting for a response */
-	      ((struct synch_state*)magic)->waiting = 0;
+	      if (magic) {
+	       ((struct synch_state*)magic)->waiting = 0;
+	      }
 	    }
 	  } else {
 	    if (SNMPV3_IGNORE_UNAUTH_REPORTS) {
 	      break;
 	    } else { /* Set the state to no longer be waiting, since we're done with retries */
-	      ((struct synch_state*)magic)->waiting = 0;
+	      if (magic) {
+	       ((struct synch_state*)magic)->waiting = 0;
+	      }
 	    }
 	  }