diff --git a/vendor/magento/module-quote/Model/QuoteMutex.php b/vendor/magento/module-quote/Model/QuoteMutex.php
new file mode 100644
index 00000000000..d1a0c050ecd
--- /dev/null
+++ b/vendor/magento/module-quote/Model/QuoteMutex.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Quote\Model;
+
+use Magento\Framework\App\ResourceConnection;
+
+/**
+ * @inheritDoc
+ */
+class QuoteMutex implements QuoteMutexInterface
+{
+    /**
+     * @var ResourceConnection
+     */
+    private $resourceConnection;
+
+    /**
+     * @param ResourceConnection $resourceConnection
+     */
+    public function __construct(
+        ResourceConnection $resourceConnection
+    ) {
+        $this->resourceConnection = $resourceConnection;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function execute(array $maskedIds, callable $callable, array $args = [])
+    {
+        if (empty($maskedIds)) {
+            throw new \InvalidArgumentException('Quote masked ids must be provided');
+        }
+
+        $connection = $this->resourceConnection->getConnection();
+        $connection->beginTransaction();
+        $query = $connection->select()
+            ->from($this->resourceConnection->getTableName('quote_id_mask'), 'entity_id')
+            ->where('masked_id IN (?)', $maskedIds)
+            ->forUpdate(true);
+        $connection->query($query);
+
+        try {
+            $result = $callable(...$args);
+            $this->resourceConnection->getConnection()->commit();
+            return $result;
+        } catch (\Throwable $e) {
+            $this->resourceConnection->getConnection()->rollBack();
+            throw $e;
+        }
+    }
+}
diff --git a/vendor/magento/module-quote/Model/QuoteMutexInterface.php b/vendor/magento/module-quote/Model/QuoteMutexInterface.php
new file mode 100644
index 00000000000..0f86b06f260
--- /dev/null
+++ b/vendor/magento/module-quote/Model/QuoteMutexInterface.php
@@ -0,0 +1,24 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Quote\Model;
+
+/**
+ * Intended to prevent race conditions during quote update by concurrent requests.
+ */
+interface QuoteMutexInterface
+{
+    /**
+     * Acquires a lock for quote, executes callable and releases the lock after.
+     *
+     * @param string[] $maskedIds
+     * @param callable $callable
+     * @param array $args
+     * @return mixed
+     */
+    public function execute(array $maskedIds, callable $callable, array $args = []);
+}
diff --git a/vendor/magento/module-quote/etc/di.xml b/vendor/magento/module-quote/etc/di.xml
index 8687f673abe..ce3a4d8a20c 100644
--- a/vendor/magento/module-quote/etc/di.xml
+++ b/vendor/magento/module-quote/etc/di.xml
@@ -45,6 +45,7 @@
     <preference for="Magento\Quote\Api\Data\ProductOptionInterface" type="Magento\Quote\Model\Quote\ProductOption" />
     <preference for="Magento\Quote\Model\ValidationRules\QuoteValidationRuleInterface" type="Magento\Quote\Model\ValidationRules\QuoteValidationComposite\Proxy"/>
     <preference for="Magento\Quote\Model\Quote\Item\Option\ComparatorInterface" type="Magento\Quote\Model\Quote\Item\Option\Comparator"/>
+    <preference for="Magento\Quote\Model\QuoteMutexInterface" type="Magento\Quote\Model\QuoteMutex"/>
     <type name="Magento\Webapi\Controller\Rest\ParamsOverrider">
         <arguments>
             <argument name="paramOverriders" xsi:type="array">
diff --git a/vendor/magento/module-quote-graph-ql/Model/Resolver/AddProductsToCart.php b/vendor/magento/module-quote-graph-ql/Model/Resolver/AddProductsToCart.php
index c7ab7596741..9f508190009 100644
--- a/vendor/magento/module-quote-graph-ql/Model/Resolver/AddProductsToCart.php
+++ b/vendor/magento/module-quote-graph-ql/Model/Resolver/AddProductsToCart.php
@@ -15,6 +15,7 @@ use Magento\GraphQl\Model\Query\ContextInterface;
 use Magento\Quote\Model\Cart\AddProductsToCart as AddProductsToCartService;
 use Magento\Quote\Model\Cart\Data\AddProductsToCartOutput;
 use Magento\Quote\Model\Cart\Data\CartItemFactory;
+use Magento\Quote\Model\QuoteMutexInterface;
 use Magento\QuoteGraphQl\Model\Cart\GetCartForUser;
 use Magento\Quote\Model\Cart\Data\Error;
 use Magento\QuoteGraphQl\Model\CartItem\DataProvider\Processor\ItemDataProcessorInterface;
@@ -41,19 +42,27 @@ class AddProductsToCart implements ResolverInterface
      */
     private $itemDataProcessor;

+    /**
+     * @var QuoteMutexInterface
+     */
+    private $quoteMutex;
+
     /**
      * @param GetCartForUser $getCartForUser
      * @param AddProductsToCartService $addProductsToCart
-     * @param  ItemDataProcessorInterface $itemDataProcessor
+     * @param ItemDataProcessorInterface $itemDataProcessor
+     * @param QuoteMutexInterface $quoteMutex
      */
     public function __construct(
         GetCartForUser $getCartForUser,
         AddProductsToCartService $addProductsToCart,
-        ItemDataProcessorInterface $itemDataProcessor
+        ItemDataProcessorInterface $itemDataProcessor,
+        QuoteMutexInterface $quoteMutex
     ) {
         $this->getCartForUser = $getCartForUser;
         $this->addProductsToCartService = $addProductsToCart;
         $this->itemDataProcessor = $itemDataProcessor;
+        $this->quoteMutex = $quoteMutex;
     }

     /**
@@ -69,13 +78,29 @@ class AddProductsToCart implements ResolverInterface
             throw new GraphQlInputException(__('Required parameter "cartItems" is missing'));
         }

+        return $this->quoteMutex->execute(
+            [$args['cartId']],
+            \Closure::fromCallable([$this, 'run']),
+            [$context, $args]
+        );
+    }
+
+    /**
+     * Run the resolver.
+     *
+     * @param ContextInterface $context
+     * @param array|null $args
+     * @return array
+     * @throws GraphQlInputException
+     */
+    private function run($context, ?array $args): array
+    {
         $maskedCartId = $args['cartId'];
         $cartItemsData = $args['cartItems'];
         $storeId = (int)$context->getExtensionAttributes()->getStore()->getId();

         // Shopping Cart validation
         $this->getCartForUser->execute($maskedCartId, $context->getUserId(), $storeId);
-
         $cartItems = [];
         foreach ($cartItemsData as $cartItemData) {
             if (!$this->itemIsAllowedToCart($cartItemData, $context)) {
diff --git a/vendor/magento/module-quote-graph-ql/Model/Resolver/AddSimpleProductsToCart.php b/vendor/magento/module-quote-graph-ql/Model/Resolver/AddSimpleProductsToCart.php
index 2135f3798d1..69a959a0a13 100644
--- a/vendor/magento/module-quote-graph-ql/Model/Resolver/AddSimpleProductsToCart.php
+++ b/vendor/magento/module-quote-graph-ql/Model/Resolver/AddSimpleProductsToCart.php
@@ -9,8 +9,10 @@ namespace Magento\QuoteGraphQl\Model\Resolver;

 use Magento\Framework\GraphQl\Config\Element\Field;
 use Magento\Framework\GraphQl\Exception\GraphQlInputException;
+use Magento\Framework\GraphQl\Query\Resolver\ContextInterface;
 use Magento\Framework\GraphQl\Query\ResolverInterface;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Quote\Model\QuoteMutexInterface;
 use Magento\QuoteGraphQl\Model\Cart\AddProductsToCart;
 use Magento\QuoteGraphQl\Model\Cart\GetCartForUser;

@@ -30,16 +32,24 @@ class AddSimpleProductsToCart implements ResolverInterface
      */
     private $addProductsToCart;

+    /**
+     * @var QuoteMutexInterface
+     */
+    private $quoteMutex;
+
     /**
      * @param GetCartForUser $getCartForUser
      * @param AddProductsToCart $addProductsToCart
+     * @param QuoteMutexInterface $quoteMutex
      */
     public function __construct(
         GetCartForUser $getCartForUser,
-        AddProductsToCart $addProductsToCart
+        AddProductsToCart $addProductsToCart,
+        QuoteMutexInterface $quoteMutex
     ) {
         $this->getCartForUser = $getCartForUser;
         $this->addProductsToCart = $addProductsToCart;
+        $this->quoteMutex = $quoteMutex;
     }

     /**
@@ -50,20 +60,37 @@ class AddSimpleProductsToCart implements ResolverInterface
         if (empty($args['input']['cart_id'])) {
             throw new GraphQlInputException(__('Required parameter "cart_id" is missing'));
         }
-        $maskedCartId = $args['input']['cart_id'];

         if (empty($args['input']['cart_items'])
             || !is_array($args['input']['cart_items'])
         ) {
             throw new GraphQlInputException(__('Required parameter "cart_items" is missing'));
         }
-        $cartItems = $args['input']['cart_items'];

+        return $this->quoteMutex->execute(
+            [$args['input']['cart_id']],
+            \Closure::fromCallable([$this, 'run']),
+            [$context, $args]
+        );
+    }
+
+    /**
+     * Run the resolver.
+     *
+     * @param ContextInterface $context
+     * @param array|null $args
+     * @return array[]
+     * @throws GraphQlInputException
+     */
+    private function run($context, ?array $args): array
+    {
+        $maskedCartId = $args['input']['cart_id'];
+        $cartItems = $args['input']['cart_items'];
         $storeId = (int)$context->getExtensionAttributes()->getStore()->getId();
         $cart = $this->getCartForUser->execute($maskedCartId, $context->getUserId(), $storeId);
         $this->addProductsToCart->execute($cart, $cartItems);
-
         $cart = $this->getCartForUser->execute($maskedCartId, $context->getUserId(), $storeId);
+
         return [
             'cart' => [
                 'model' => $cart,