diff --git a/libraries/classes/Plugins/Auth/AuthenticationCookie.php b/libraries/classes/Plugins/Auth/AuthenticationCookie.php
index 0a8000c948..f3f1e3a5a5 100644
--- a/libraries/classes/Plugins/Auth/AuthenticationCookie.php
+++ b/libraries/classes/Plugins/Auth/AuthenticationCookie.php
@@ -331,7 +331,13 @@ class AuthenticationCookie extends AuthenticationPlugin
 
             // The user just logged in
             $this->user = Core::sanitizeMySQLUser($_POST['pma_username']);
-            $this->password = $_POST['pma_password'] ?? '';
+
+            $password = $_POST['pma_password'] ?? '';
+            if (strlen($password) > 256) {
+                $password = substr($password, 0, 256);
+            }
+            $this->password = $password;
+
             if ($GLOBALS['cfg']['AllowArbitraryServer']
                 && isset($_REQUEST['pma_servername'])
             ) {
diff --git a/libraries/common.inc.php b/libraries/common.inc.php
index 06884a61a1..eba4e33809 100644
--- a/libraries/common.inc.php
+++ b/libraries/common.inc.php
@@ -264,10 +264,6 @@ if (! defined('PMA_MINIMUM_COMMON')) {
         }
         unset($cache_key);
 
-        if (isset($_POST['pma_password']) && strlen($_POST['pma_password']) > 256) {
-            $_POST['pma_password'] = substr($_POST['pma_password'], 0, 256);
-        }
-
         $auth_plugin = Plugins::getAuthPlugin();
         $auth_plugin->authenticate();