diff --git a/srtp/srtp.c b/srtp/srtp.c
index ea83168..4cc7be7 100644
--- a/srtp/srtp.c
+++ b/srtp/srtp.c
@@ -889,6 +889,8 @@
             srtp_hdr_xtnd_t *xtn_hdr = (srtp_hdr_xtnd_t*)enc_start;
             enc_start += (ntohs(xtn_hdr->length) + 1);
         }
+        if (!(enc_start < (uint32_t*)hdr + *pkt_octet_len))
+            return err_status_parse_err;
         enc_octet_len = (unsigned int)(*pkt_octet_len - 
 		        ((enc_start - (uint32_t*)hdr) << 2));
     } else {
@@ -1017,6 +1019,8 @@
         srtp_hdr_xtnd_t *xtn_hdr = (srtp_hdr_xtnd_t*)enc_start;
         enc_start += (ntohs(xtn_hdr->length) + 1);
     }
+    if (!(enc_start < (uint32_t*)hdr + *pkt_octet_len))
+        return err_status_parse_err;
     /*
      * We pass the tag down to the cipher when doing GCM mode 
      */
@@ -1240,6 +1244,8 @@
      if (hdr->x == 1) {
        srtp_hdr_xtnd_t *xtn_hdr = (srtp_hdr_xtnd_t *)enc_start;
        enc_start += (ntohs(xtn_hdr->length) + 1);
+       if (!(enc_start < (uint32_t*)hdr + *pkt_octet_len))
+         return err_status_parse_err;
      }
      enc_octet_len = (unsigned int)(*pkt_octet_len 
 				    - ((enc_start - (uint32_t *)hdr) << 2));
@@ -1521,6 +1527,8 @@
       srtp_hdr_xtnd_t *xtn_hdr = (srtp_hdr_xtnd_t *)enc_start;
       enc_start += (ntohs(xtn_hdr->length) + 1);
     }  
+    if (!(enc_start < (uint32_t*)hdr + *pkt_octet_len))
+      return err_status_parse_err;
     enc_octet_len = (uint32_t)(*pkt_octet_len - tag_len 
 			       - ((enc_start - (uint32_t *)hdr) << 2));
   } else {