diff --git a/libxrdp/xrdp_sec.c b/libxrdp/xrdp_sec.c
index dd55beb9..8a4bc945 100644
--- a/libxrdp/xrdp_sec.c
+++ b/libxrdp/xrdp_sec.c
@@ -1903,6 +1903,10 @@ xrdp_sec_process_mcs_data_CS_SECURITY(struct xrdp_sec *self, struct stream *s)
     int crypt_method;
     int found;
 
+    if (!s_check_rem_and_log(s, 4, "Parsing [MS-RDPBCGR] CS_SECURITY"))
+    {
+        return 1;
+    }
     in_uint32_le(s, crypt_method);
     LOG_DEVEL(LOG_LEVEL_TRACE, "Received [MS-RDPBCGR] TS_UD_CS_SEC "
               "encryptionMethods 0x%8.8x, extEncryptionMethods (ignored)",