diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 2534346..585750e 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2057,6 +2057,12 @@
      *
      * opaque psk_identity_hint<0..2^16-1>;
      */
+    if( (*p) > end - 2 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
+                                    "(psk_identity_hint length)" ) );
+        return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+    }
     len = (*p)[0] << 8 | (*p)[1];
     *p += 2;