diff --git a/libraries/common.inc.php b/libraries/common.inc.php
index 4922999b91..1a3782eee8 100644
--- a/libraries/common.inc.php
+++ b/libraries/common.inc.php
@@ -639,7 +639,7 @@ if (! defined('PMA_MINIMUM_COMMON')) {
                 . ' ' . $cfg['Server']['auth_type']
             );
         }
-        if (isset($_REQUEST['pma_password'])) {
+        if (isset($_REQUEST['pma_password']) && strlen($_REQUEST['pma_password']) > 256) {
             $_REQUEST['pma_password'] = substr($_REQUEST['pma_password'], 0, 256);
         }
         $fqnAuthClass = 'PMA\libraries\plugins\auth\\' . $auth_class;