diff --git a/decoder/ihevcd_parse_headers.c b/decoder/ihevcd_parse_headers.c
index b560a39..c0f1564 100644
--- a/decoder/ihevcd_parse_headers.c
+++ b/decoder/ihevcd_parse_headers.c
@@ -644,6 +644,9 @@
         if(!ps_hrd->au1_low_delay_hrd_flag[i])
             UEV_PARSE("cpb_cnt_minus1[ i ]", ps_hrd->au1_cpb_cnt_minus1[i], ps_bitstrm);
 
+        if(ps_hrd->au1_cpb_cnt_minus1[i] >= (MAX_CPB_CNT - 1))
+            return IHEVCD_INVALID_PARAMETER;
+
         if(ps_hrd->u1_nal_hrd_parameters_present_flag)
             ihevcd_parse_sub_layer_hrd_parameters(ps_bitstrm,
                                                   &ps_hrd->as_sub_layer_hrd_params[i],
@@ -744,7 +747,10 @@
 
         BITS_PARSE("vui_hrd_parameters_present_flag", ps_vui->u1_vui_hrd_parameters_present_flag, ps_bitstrm, 1);
         if(ps_vui->u1_vui_hrd_parameters_present_flag)
-            ihevcd_parse_hrd_parameters(ps_bitstrm, &ps_vui->s_vui_hrd_parameters, 1, sps_max_sub_layers_minus1);
+        {
+            ret = ihevcd_parse_hrd_parameters(ps_bitstrm, &ps_vui->s_vui_hrd_parameters, 1, sps_max_sub_layers_minus1);
+            RETURN_IF((ret != (IHEVCD_ERROR_T)IHEVCD_SUCCESS), ret);
+        }
     }
 
     BITS_PARSE("bitstream_restriction_flag", ps_vui->u1_bitstream_restriction_flag, ps_bitstrm, 1);
@@ -1224,6 +1230,12 @@
 
 
     ps_sps = (ps_codec->s_parse.ps_sps_base + MAX_SPS_CNT - 1);
+    /* Reset SPS to zero */
+    {
+        WORD16 *pi2_scaling_mat = ps_sps->pi2_scaling_mat;
+        memset(ps_sps, 0, sizeof(sps_t));
+        ps_sps->pi2_scaling_mat = pi2_scaling_mat;
+    }
     ps_sps->i1_sps_id = sps_id;
     ps_sps->i1_vps_id = vps_id;
     ps_sps->i1_sps_max_sub_layers = sps_max_sub_layers;
@@ -1330,6 +1342,35 @@
         UEV_PARSE("max_latency_increase", value, ps_bitstrm);
         ps_sps->ai1_sps_max_latency_increase[i] = value;
     }
+
+    /* Check if sps_max_dec_pic_buffering or sps_max_num_reorder_pics
+       has changed */
+    if(0 != ps_codec->u4_allocate_dynamic_done)
+    {
+        sps_t *ps_sps_old = ps_codec->s_parse.ps_sps;
+        if(ps_sps_old->ai1_sps_max_dec_pic_buffering[ps_sps_old->i1_sps_max_sub_layers - 1] !=
+                    ps_sps->ai1_sps_max_dec_pic_buffering[ps_sps->i1_sps_max_sub_layers - 1])
+        {
+            if(0 == ps_codec->i4_first_pic_done)
+            {
+                return IHEVCD_INVALID_PARAMETER;
+            }
+            ps_codec->i4_reset_flag = 1;
+            return (IHEVCD_ERROR_T)IVD_RES_CHANGED;
+        }
+
+        if(ps_sps_old->ai1_sps_max_num_reorder_pics[ps_sps_old->i1_sps_max_sub_layers - 1] !=
+                    ps_sps->ai1_sps_max_num_reorder_pics[ps_sps->i1_sps_max_sub_layers - 1])
+        {
+            if(0 == ps_codec->i4_first_pic_done)
+            {
+                return IHEVCD_INVALID_PARAMETER;
+            }
+            ps_codec->i4_reset_flag = 1;
+            return (IHEVCD_ERROR_T)IVD_RES_CHANGED;
+        }
+    }
+
     UEV_PARSE("log2_min_coding_block_size_minus3", value, ps_bitstrm);
     ps_sps->i1_log2_min_coding_block_size = value + 3;
 
@@ -1456,9 +1497,12 @@
     ps_sps->i1_vui_parameters_present_flag = value;
 
     if(ps_sps->i1_vui_parameters_present_flag)
-        ihevcd_parse_vui_parameters(ps_bitstrm,
-                                    &ps_sps->s_vui_parameters,
-                                    ps_sps->i1_sps_max_sub_layers - 1);
+    {
+        ret = ihevcd_parse_vui_parameters(ps_bitstrm,
+                                          &ps_sps->s_vui_parameters,
+                                          ps_sps->i1_sps_max_sub_layers - 1);
+        RETURN_IF((ret != (IHEVCD_ERROR_T)IHEVCD_SUCCESS), ret);
+    }
 
     BITS_PARSE("sps_extension_flag", value, ps_bitstrm, 1);
 
@@ -1495,10 +1539,14 @@
         ps_sps->i2_pic_ht_in_min_cb = numerator  /
                         (1 << ps_sps->i1_log2_min_coding_block_size);
     }
-    if((0 != ps_codec->i4_first_pic_done) &&
+    if((0 != ps_codec->u4_allocate_dynamic_done) &&
                     ((ps_codec->i4_wd != ps_sps->i2_pic_width_in_luma_samples) ||
                     (ps_codec->i4_ht != ps_sps->i2_pic_height_in_luma_samples)))
     {
+        if(0 == ps_codec->i4_first_pic_done)
+        {
+            return IHEVCD_INVALID_PARAMETER;
+        }
         ps_codec->i4_reset_flag = 1;
         return (IHEVCD_ERROR_T)IVD_RES_CHANGED;
     }
@@ -1926,6 +1974,9 @@
     /* Not present in HM */
     BITS_PARSE("pps_extension_flag", value, ps_bitstrm, 1);
 
+    if((UWORD8 *)ps_bitstrm->pu4_buf > ps_bitstrm->pu1_buf_max)
+        return IHEVCD_INVALID_PARAMETER;
+
     ps_codec->i4_pps_done = 1;
     return ret;
 }
diff --git a/decoder/ihevcd_parse_slice_header.c b/decoder/ihevcd_parse_slice_header.c
index 62ad6c8..e1b50b7 100644
--- a/decoder/ihevcd_parse_slice_header.c
+++ b/decoder/ihevcd_parse_slice_header.c
@@ -257,10 +257,11 @@
     {
         pps_t *ps_pps_ref = ps_codec->ps_pps_base;
         while(0 == ps_pps_ref->i1_pps_valid)
+        {
             ps_pps_ref++;
-
-        if((ps_pps_ref - ps_codec->ps_pps_base >= MAX_PPS_CNT - 1))
-            return IHEVCD_INVALID_HEADER;
+            if((ps_pps_ref - ps_codec->ps_pps_base >= MAX_PPS_CNT - 1))
+                return IHEVCD_INVALID_HEADER;
+        }
 
         ihevcd_copy_pps(ps_codec, pps_id, ps_pps_ref->i1_pps_id);
     }
@@ -862,6 +863,9 @@
 
     ihevcd_bits_flush_to_byte_boundary(ps_bitstrm);
 
+    if((UWORD8 *)ps_bitstrm->pu4_buf > ps_bitstrm->pu1_buf_max)
+        return IHEVCD_INVALID_PARAMETER;
+
     {
         dpb_mgr_t *ps_dpb_mgr = (dpb_mgr_t *)ps_codec->pv_dpb_mgr;
         WORD32 r_idx;