Index: branches/version-2_12-dev/data/class/pages/cart/LC_Page_Cart.php
===================================================================
--- branches/version-2_12-dev/data/class/pages/cart/LC_Page_Cart.php	(revision 22567)
+++ branches/version-2_12-dev/data/class/pages/cart/LC_Page_Cart.php	(revision 22604)
@@ -87,5 +87,5 @@
         $objCustomer = new SC_Customer_Ex();
 
-        $objFormParam = $this->lfInitParam($_REQUEST);
+        $objFormParam = $this->lfInitParam($_POST);
         $this->mode = $this->getMode();
 
@@ -100,4 +100,11 @@
         $cart_no = $objFormParam->getValue('cart_no');
         $cartKey = $objFormParam->getValue('cartKey');
+        
+        // エラーチェック
+        $arrError = $objFormParam->checkError();
+        if(isset($arrError) && !empty($arrError)) {
+            SC_Utils_Ex::sfDispSiteError(CART_NOT_FOUND);
+            SC_Response_Ex::actionExit();
+        }
 
         switch ($this->mode) {
@@ -213,5 +220,5 @@
         $objFormParam->addParam('カテゴリID', 'category_id', INT_LEN, 'n', array('NUM_CHECK', 'MAX_LENGTH_CHECK'));
         // スマートフォン版での数量変更用
-        $objFormParam->addParam('数量', 'quantity', INT_LEN, 'n', array('EXIST_CHECK', 'ZERO_CHECK', 'NUM_CHECK', 'MAX_LENGTH_CHECK'));
+        $objFormParam->addParam('数量', 'quantity', INT_LEN, 'n', array('ZERO_CHECK', 'NUM_CHECK', 'MAX_LENGTH_CHECK'));
         // 値の取得
         $objFormParam->setParam($arrRequest);