Fix #20447: Fix behavior for yii\web\Controller::bindActionParams around mixed type

framework/CHANGELOG.md

@@ -14,6 +14,7 @@ Yii Framework 2 Change Log
 - Bug #20459: Fix return type in `RequestParserInterface::parse` (max-s-lab)
 - Bug #20475: Fix `Formatter` class `asScientific()` method for PHP `8.5` `sprintf` precision change (`6` to `0`) (terabytesoftw)
 - Enh #20480: Add PHPStan/Psalm annotations for `ServiceLocator::get` (max-s-lab)
+- Bug #20447: Fix behavior for `yii\web\Controller::bindActionParams` around `mixed` type (chriscpty)
 
 2.0.53 June 27, 2025
 --------------------

framework/web/Controller.php

@@ -208,6 +208,10 @@ class Controller extends \yii\base\Controller
         if ($isArray) {
             return [(array)$param, true];
         }
+        $isMixed = $type->getName() === 'mixed';
+        if ($isMixed) {
+            return [$param, true];
+        }
 
         if (is_array($param)) {
             return [$param, false];