diff --git a/common/ihevc_defs.h b/common/ihevc_defs.h
index 5360ff2..5f469e6 100644
--- a/common/ihevc_defs.h
+++ b/common/ihevc_defs.h
@@ -294,10 +294,14 @@ typedef enum {
 /* CTB Size Range */
 #define MAX_CTB_SIZE        64
 #define MIN_CTB_SIZE        16
+#define LOG2_MAX_CTB_SIZE   6
+#define LOG2_MIN_CTB_SIZE   4
 
 /* TU Size Range */
 #define MAX_TU_SIZE         32
 #define MIN_TU_SIZE         4
+#define LOG2_MAX_TU_SIZE    5
+#define LOG2_MIN_TU_SIZE    2
 
 /* Max Transform Size */
 #define MAX_TRANS_SIZE      (MAX_TU_SIZE*MAX_TU_SIZE)
@@ -305,11 +309,14 @@ typedef enum {
 /* PU Size Range */
 #define MAX_PU_SIZE         64
 #define MIN_PU_SIZE         4
+#define LOG2_MAX_PU_SIZE    6
+#define LOG2_MIN_PU_SIZE    2
 
 /* CU Size Range */
 #define MAX_CU_SIZE         64
 #define MIN_CU_SIZE         8
-
+#define LOG2_MAX_CU_SIZE    6
+#define LOG2_MIN_CU_SIZE    3
 
 /* Number of max TU in a CTB row */
 #define MAX_TU_IN_CTB_ROW   ((MAX_CTB_SIZE / MIN_TU_SIZE))
diff --git a/decoder/ihevcd_parse_headers.c b/decoder/ihevcd_parse_headers.c
index 8a09bb1..8743b8b 100644
--- a/decoder/ihevcd_parse_headers.c
+++ b/decoder/ihevcd_parse_headers.c
@@ -1381,17 +1381,37 @@ IHEVCD_ERROR_T ihevcd_parse_sps(codec_t *ps_codec)
     }
 
     UEV_PARSE("log2_min_coding_block_size_minus3", value, ps_bitstrm);
+    if(value > (LOG2_MAX_CU_SIZE - 3))
+    {
+        return IHEVCD_INVALID_PARAMETER;
+    }
     ps_sps->i1_log2_min_coding_block_size = value + 3;
 
     UEV_PARSE("log2_diff_max_min_coding_block_size", value, ps_bitstrm);
+    if(value > (LOG2_MAX_CU_SIZE - LOG2_MIN_CU_SIZE))
+    {
+        return IHEVCD_INVALID_PARAMETER;
+    }
     ps_sps->i1_log2_diff_max_min_coding_block_size = value;
 
     ctb_log2_size_y = ps_sps->i1_log2_min_coding_block_size + ps_sps->i1_log2_diff_max_min_coding_block_size;
 
     UEV_PARSE("log2_min_transform_block_size_minus2", value, ps_bitstrm);
+    if(value > (LOG2_MAX_TU_SIZE - 2))
+    {
+        return IHEVCD_INVALID_PARAMETER;
+    }
     ps_sps->i1_log2_min_transform_block_size = value + 2;
+    if(ps_sps->i1_log2_min_transform_block_size >= ps_sps->i1_log2_min_coding_block_size)
+    {
+        return IHEVCD_INVALID_PARAMETER;
+    }
 
     UEV_PARSE("log2_diff_max_min_transform_block_size", value, ps_bitstrm);
+    if(value > (LOG2_MAX_TU_SIZE - LOG2_MIN_TU_SIZE))
+    {
+        return IHEVCD_INVALID_PARAMETER;
+    }
     ps_sps->i1_log2_diff_max_min_transform_block_size = value;
 
     ps_sps->i1_log2_max_transform_block_size = ps_sps->i1_log2_min_transform_block_size +