diff --git a/src/sgwc/s5c-handler.c b/src/sgwc/s5c-handler.c
index 63f88e128..aea8943ce 100644
--- a/src/sgwc/s5c-handler.c
+++ b/src/sgwc/s5c-handler.c
@@ -79,9 +79,6 @@ void sgwc_s5c_handle_create_session_response(
     ogs_gtp_xact_t *s11_xact = NULL;
     ogs_gtp_node_t *pgw = NULL;
 
-    ogs_assert(sess);
-    sgwc_ue = sess->sgwc_ue;
-    ogs_assert(sgwc_ue);
     ogs_assert(gtpbuf);
     ogs_assert(message);
     rsp = &message->create_session_response;
@@ -99,10 +96,32 @@ void sgwc_s5c_handle_create_session_response(
     rv = ogs_gtp_xact_commit(s5c_xact);
     ogs_expect(rv == OGS_OK);
 
+    /************************
+     * Check Session Context
+     *
+     * - Session could be deleted before a message is received from SMF.
+     ************************/
+    cause_value = OGS_GTP2_CAUSE_REQUEST_ACCEPTED;
+
+    if (!sess) {
+        ogs_error("No Context in TEID");
+        cause_value = OGS_GTP2_CAUSE_CONTEXT_NOT_FOUND;
+    } else {
+        sgwc_ue = sess->sgwc_ue;
+        ogs_assert(sgwc_ue);
+    }
+
+    if (cause_value != OGS_GTP2_CAUSE_REQUEST_ACCEPTED) {
+        ogs_gtp_send_error_message(
+                s11_xact, sgwc_ue ? sgwc_ue->mme_s11_teid : 0,
+                OGS_GTP2_CREATE_SESSION_RESPONSE_TYPE, cause_value);
+        return;
+    }
+
     /*****************************************
      * Check Mandatory/Conditional IE Missing
      *****************************************/
-    cause_value = OGS_GTP2_CAUSE_REQUEST_ACCEPTED;
+    ogs_assert(cause_value == OGS_GTP2_CAUSE_REQUEST_ACCEPTED);
 
     if (rsp->pgw_s5_s8__s2a_s2b_f_teid_for_pmip_based_interface_or_for_gtp_based_control_plane_interface.presence == 0) {
         ogs_error("No GTP TEID");
@@ -280,9 +299,6 @@ void sgwc_s5c_handle_modify_bearer_response(
     ogs_gtp_xact_t *s11_xact = NULL;
     ogs_gtp2_modify_bearer_response_t *rsp = NULL;
 
-    ogs_assert(sess);
-    sgwc_ue = sess->sgwc_ue;
-    ogs_assert(sgwc_ue);
     ogs_assert(message);
     rsp = &message->modify_bearer_response;
     ogs_assert(rsp);
@@ -300,10 +316,37 @@ void sgwc_s5c_handle_modify_bearer_response(
     rv = ogs_gtp_xact_commit(s5c_xact);
     ogs_expect(rv == OGS_OK);
 
+    /************************
+     * Check Session Context
+     *
+     * - Session could be deleted before a message is received from SMF.
+     ************************/
+    cause_value = OGS_GTP2_CAUSE_REQUEST_ACCEPTED;
+
+    if (!sess) {
+        ogs_error("No Context in TEID");
+        cause_value = OGS_GTP2_CAUSE_CONTEXT_NOT_FOUND;
+    } else {
+        sgwc_ue = sess->sgwc_ue;
+        ogs_assert(sgwc_ue);
+    }
+
+    if (cause_value != OGS_GTP2_CAUSE_REQUEST_ACCEPTED) {
+        if (modify_action == OGS_GTP_MODIFY_IN_PATH_SWITCH_REQUEST)
+            ogs_gtp_send_error_message(
+                    s11_xact, sgwc_ue ? sgwc_ue->mme_s11_teid : 0,
+                    OGS_GTP2_CREATE_SESSION_RESPONSE_TYPE, cause_value);
+        else
+            ogs_gtp_send_error_message(
+                    s11_xact, sgwc_ue ? sgwc_ue->mme_s11_teid : 0,
+                    OGS_GTP2_MODIFY_BEARER_RESPONSE_TYPE, cause_value);
+        return;
+    }
+
     /*****************************************
      * Check Mandatory/Conditional IE Missing
      *****************************************/
-    cause_value = OGS_GTP2_CAUSE_REQUEST_ACCEPTED;
+    ogs_assert(cause_value == OGS_GTP2_CAUSE_REQUEST_ACCEPTED);
 
     if (rsp->cause.presence == 0) {
         ogs_error("No Cause");
@@ -385,9 +428,6 @@ void sgwc_s5c_handle_delete_session_response(
     ogs_gtp_xact_t *s11_xact = NULL;
     ogs_gtp2_delete_session_response_t *rsp = NULL;
 
-    ogs_assert(sess);
-    sgwc_ue = sess->sgwc_ue;
-    ogs_assert(sgwc_ue);
     ogs_assert(message);
     rsp = &message->delete_session_response;
     ogs_assert(rsp);
@@ -404,10 +444,32 @@ void sgwc_s5c_handle_delete_session_response(
     rv = ogs_gtp_xact_commit(s5c_xact);
     ogs_expect(rv == OGS_OK);
 
+    /************************
+     * Check Session Context
+     *
+     * - Session could be deleted before a message is received from SMF.
+     ************************/
+    cause_value = OGS_GTP2_CAUSE_REQUEST_ACCEPTED;
+
+    if (!sess) {
+        ogs_error("No Context in TEID");
+        cause_value = OGS_GTP2_CAUSE_CONTEXT_NOT_FOUND;
+    } else {
+        sgwc_ue = sess->sgwc_ue;
+        ogs_assert(sgwc_ue);
+    }
+
+    if (cause_value != OGS_GTP2_CAUSE_REQUEST_ACCEPTED) {
+        ogs_gtp_send_error_message(
+                s11_xact, sgwc_ue ? sgwc_ue->mme_s11_teid : 0,
+                OGS_GTP2_DELETE_SESSION_RESPONSE_TYPE, cause_value);
+        return;
+    }
+
     /*****************************************
      * Check Mandatory/Conditional IE Missing
      *****************************************/
-    cause_value = OGS_GTP2_CAUSE_REQUEST_ACCEPTED;
+    ogs_assert(cause_value == OGS_GTP2_CAUSE_REQUEST_ACCEPTED);
 
     if (rsp->cause.presence == 0) {
         ogs_error("No Cause");
@@ -835,9 +897,6 @@ void sgwc_s5c_handle_bearer_resource_failure_indication(
 
     sgwc_ue_t *sgwc_ue = NULL;
 
-    ogs_assert(sess);
-    sgwc_ue = sess->sgwc_ue;
-    ogs_assert(sgwc_ue);
     ogs_assert(message);
     ind = &message->bearer_resource_failure_indication;
     ogs_assert(ind);
@@ -851,6 +910,19 @@ void sgwc_s5c_handle_bearer_resource_failure_indication(
     s11_xact = s5c_xact->assoc_xact;
     ogs_assert(s11_xact);
 
+    /************************
+     * Check Session Context
+     *
+     * - Session could be deleted before a message is received from SMF.
+     ************************/
+    if (!sess) {
+        ogs_error("No Context in TEID");
+        cause_value = OGS_GTP2_CAUSE_CONTEXT_NOT_FOUND;
+    } else {
+        sgwc_ue = sess->sgwc_ue;
+        ogs_assert(sgwc_ue);
+    }
+
     /********************
      * Check Cause Value
      ********************/
diff --git a/src/sgwc/sxa-handler.c b/src/sgwc/sxa-handler.c
index 59c61c7dd..c86c95962 100644
--- a/src/sgwc/sxa-handler.c
+++ b/src/sgwc/sxa-handler.c
@@ -1325,12 +1325,21 @@ void sgwc_sxa_handle_session_report_request(
 
     ogs_debug("Session Report Request");
 
-    ogs_assert(sess);
     ogs_assert(pfcp_xact);
     ogs_assert(pfcp_req);
 
     cause_value = OGS_GTP2_CAUSE_REQUEST_ACCEPTED;
 
+    /************************
+     * Check Session Context
+     *
+     * - Session could be deleted before a message is received from SMF.
+     ************************/
+    if (!sess) {
+        ogs_error("No Context");
+        cause_value = OGS_PFCP_CAUSE_SESSION_CONTEXT_NOT_FOUND;
+    }
+
     if (pfcp_req->report_type.presence == 0) {
         ogs_error("No Report Type");
         cause_value = OGS_GTP2_CAUSE_MANDATORY_IE_MISSING;