diff --git a/mysql-test/main/gis.result b/mysql-test/main/gis.result
index 0fe92b2f50c13..d60f8da2d5d51 100644
--- a/mysql-test/main/gis.result
+++ b/mysql-test/main/gis.result
@@ -5644,4 +5644,13 @@ NULL
 SELECT ST_GEOMFROMWKB (0x01050000000100000082040000000100000000000000000000000000000000000000) as g;
 g
 NULL
+#
+# MDEV-40552 UBSAN : load of value X, which is not a valid value for type 'wkbByteOrder' Gis_multi_point::init_from_wkb
+#
+SELECT ST_GEOMFROMWKB (0x0104000000010000000201000000000000000000000000000000000000000000000000) as multipoint_bad_inner_bo;
+multipoint_bad_inner_bo
+NULL
+SELECT ST_GEOMFROMWKB (0x0104000000010000008201000000000000000000000000000000000000000000000000) as multipoint_bad_inner_bo;
+multipoint_bad_inner_bo
+NULL
 # End of 10.11 tests
diff --git a/mysql-test/main/gis.test b/mysql-test/main/gis.test
index 609c1509396f5..1efed8d076903 100644
--- a/mysql-test/main/gis.test
+++ b/mysql-test/main/gis.test
@@ -3605,4 +3605,11 @@ SELECT ST_GEOMFROMWKB (0x01070000000100000082010000000000000000000000) as g;
 SELECT ST_GEOMFROMWKB (0x01050000000100000002040000000100000000000000000000000000000000000000) as g;
 SELECT ST_GEOMFROMWKB (0x01050000000100000082040000000100000000000000000000000000000000000000) as g;
 
+--echo #
+--echo # MDEV-40552 UBSAN : load of value X, which is not a valid value for type 'wkbByteOrder' Gis_multi_point::init_from_wkb
+--echo #
+
+SELECT ST_GEOMFROMWKB (0x0104000000010000000201000000000000000000000000000000000000000000000000) as multipoint_bad_inner_bo;
+SELECT ST_GEOMFROMWKB (0x0104000000010000008201000000000000000000000000000000000000000000000000) as multipoint_bad_inner_bo;
+
 --echo # End of 10.11 tests
diff --git a/sql/spatial.cc b/sql/spatial.cc
index 2de3c57ef1a11..979bac0954533 100644
--- a/sql/spatial.cc
+++ b/sql/spatial.cc
@@ -2180,6 +2180,8 @@ uint Gis_multi_point::init_from_wkb(const char *wkb, uint len, wkbByteOrder bo,
   {
     res->q_append((char)wkb_ndr);
     res->q_append((uint32)wkb_point);
+    if ((uchar) wkb[0] > wkb_ndr) /* invalid */
+      return 0;
     if (!p.init_from_wkb(wkb + WKB_HEADER_SIZE,
                          POINT_DATA_SIZE, (wkbByteOrder) wkb[0], res))
       return 0;