diff --git a/src/lib/openjp2/j2k.c b/src/lib/openjp2/j2k.c
index 842c8caa..c45b6742 100644
--- a/src/lib/openjp2/j2k.c
+++ b/src/lib/openjp2/j2k.c
@@ -2707,6 +2707,12 @@ static OPJ_BOOL opj_j2k_read_cod(opj_j2k_t *p_j2k,
     opj_read_bytes(p_header_data, &l_tcp->mct, 1);          /* SGcod (C) */
     ++p_header_data;
 
+    if (l_tcp->mct > 1) {
+        opj_event_msg(p_manager, EVT_ERROR,
+                      "Invalid multiple component transformation\n");
+        return OPJ_FALSE;
+    }
+
     p_header_size -= 5;
     for (i = 0; i < l_image->numcomps; ++i) {
         l_tcp->tccps[i].csty = l_tcp->csty & J2K_CCP_CSTY_PRT;
@@ -10507,9 +10513,9 @@ static OPJ_BOOL opj_j2k_read_SPCod_SPCoc(opj_j2k_t *p_j2k,
         return OPJ_FALSE;
     }
 
-    opj_read_bytes(l_current_ptr, &l_tccp->numresolutions,
-                   1);              /* SPcox (D) */
-    ++l_tccp->numresolutions;                                                                               /* tccp->numresolutions = read() + 1 */
+    /* SPcod (D) / SPcoc (A) */
+    opj_read_bytes(l_current_ptr, &l_tccp->numresolutions, 1);
+    ++l_tccp->numresolutions;  /* tccp->numresolutions = read() + 1 */
     if (l_tccp->numresolutions > OPJ_J2K_MAXRLVLS) {
         opj_event_msg(p_manager, EVT_ERROR,
                       "Invalid value for numresolutions : %d, max value is set in openjpeg.h at %d\n",
@@ -10530,11 +10536,13 @@ static OPJ_BOOL opj_j2k_read_SPCod_SPCoc(opj_j2k_t *p_j2k,
         return OPJ_FALSE;
     }
 
-    opj_read_bytes(l_current_ptr, &l_tccp->cblkw, 1);               /* SPcoc (E) */
+    /* SPcod (E) / SPcoc (B) */
+    opj_read_bytes(l_current_ptr, &l_tccp->cblkw, 1);
     ++l_current_ptr;
     l_tccp->cblkw += 2;
 
-    opj_read_bytes(l_current_ptr, &l_tccp->cblkh, 1);               /* SPcoc (F) */
+    /* SPcod (F) / SPcoc (C) */
+    opj_read_bytes(l_current_ptr, &l_tccp->cblkh, 1);
     ++l_current_ptr;
     l_tccp->cblkh += 2;
 
@@ -10545,8 +10553,8 @@ static OPJ_BOOL opj_j2k_read_SPCod_SPCoc(opj_j2k_t *p_j2k,
         return OPJ_FALSE;
     }
 
-
-    opj_read_bytes(l_current_ptr, &l_tccp->cblksty, 1);             /* SPcoc (G) */
+    /* SPcod (G) / SPcoc (D) */
+    opj_read_bytes(l_current_ptr, &l_tccp->cblksty, 1);
     ++l_current_ptr;
     if (l_tccp->cblksty & 0xC0U) { /* 2 msb are reserved, assume we can't read */
         opj_event_msg(p_manager, EVT_ERROR,
@@ -10554,9 +10562,16 @@ static OPJ_BOOL opj_j2k_read_SPCod_SPCoc(opj_j2k_t *p_j2k,
         return OPJ_FALSE;
     }
 
-    opj_read_bytes(l_current_ptr, &l_tccp->qmfbid, 1);              /* SPcoc (H) */
+    /* SPcod (H) / SPcoc (E) */
+    opj_read_bytes(l_current_ptr, &l_tccp->qmfbid, 1);
     ++l_current_ptr;
 
+    if (l_tccp->qmfbid > 1) {
+        opj_event_msg(p_manager, EVT_ERROR,
+                      "Error reading SPCod SPCoc element, Invalid transformation found\n");
+        return OPJ_FALSE;
+    }
+
     *p_header_size = *p_header_size - 5;
 
     /* use custom precinct size ? */
@@ -10566,8 +10581,9 @@ static OPJ_BOOL opj_j2k_read_SPCod_SPCoc(opj_j2k_t *p_j2k,
             return OPJ_FALSE;
         }
 
+        /* SPcod (I_i) / SPcoc (F_i) */
         for (i = 0; i < l_tccp->numresolutions; ++i) {
-            opj_read_bytes(l_current_ptr, &l_tmp, 1);               /* SPcoc (I_i) */
+            opj_read_bytes(l_current_ptr, &l_tmp, 1);
             ++l_current_ptr;
             /* Precinct exponent 0 is only allowed for lowest resolution level (Table A.21) */
             if ((i != 0) && (((l_tmp & 0xf) == 0) || ((l_tmp >> 4) == 0))) {
diff --git a/tests/nonregression/CMakeLists.txt b/tests/nonregression/CMakeLists.txt
index 9f956b90..b1303ad8 100644
--- a/tests/nonregression/CMakeLists.txt
+++ b/tests/nonregression/CMakeLists.txt
@@ -34,7 +34,6 @@ set(BLACKLIST_JPEG2000_TMP
     edf_c2_1178956.jp2
     edf_c2_1000290.jp2
     #edf_c2_1000691.jp2 # ok
-    #edf_c2_20.jp2 #looks ok as per kdu_jp2info
     edf_c2_1377017.jp2
     edf_c2_1002767.jp2
     edf_c2_10025.jp2
@@ -61,6 +60,7 @@ set(BLACKLIST_JPEG2000
     broken2.jp2
     broken3.jp2
     broken4.jp2
+    edf_c2_20.jp2 #may look ok as per kdu_jp2info, but inspection it reveals that the transformation value is out of range
     gdal_fuzzer_assert_in_opj_j2k_read_SQcd_SQcc.patch.jp2	
     gdal_fuzzer_check_comp_dx_dy.jp2
     gdal_fuzzer_check_number_of_tiles.jp2
@@ -82,6 +82,8 @@ set(BLACKLIST_JPEG2000
     issue475.jp2 #kdu_jp2info ok
     issue413.jp2 #kdu_jp2info ok
     issue823.jp2 #kdu_jp2info ok
+    issue826.jp2 #inspection reveales that the transformation value is out of range
+    oss-fuzz2785.jp2 #inspection reveales that the transformation value is out of range
    )
 
 file(GLOB_RECURSE OPJ_DATA_NR_LIST