diff --git a/vendor/magento/module-paypal/Controller/Express/AbstractExpress.php b/vendor/magento/module-paypal/Controller/Express/AbstractExpress.php
index 65426cb5f7203..0900ef30e0fb0 100644
--- a/vendor/magento/module-paypal/Controller/Express/AbstractExpress.php
+++ b/vendor/magento/module-paypal/Controller/Express/AbstractExpress.php
@@ -151,7 +151,7 @@ public function __construct(
     protected function _initCheckout(CartInterface $quoteObject = null)
     {
         $quote = $quoteObject ? $quoteObject : $this->_getQuote();
-        if ($quote->getId()) {
+        if ($quote->getId() && $this->isQuoteAllowedForUser($quote)) {
             $this->_getCheckoutSession()->setPayPalQuoteId($quote->getId());
         }
         if (!$quote->hasItems() || $quote->getHasError()) {
@@ -259,6 +259,22 @@ protected function _getQuote()
         return $this->_quote;
     }
 
+    /**
+     * Checks if the quote is allowed for the current user.
+     *
+     * @param CartInterface $quote
+     * @return bool
+     */
+    private function isQuoteAllowedForUser(CartInterface $quote): bool
+    {
+        if ((int)$quote->getId() === (int)$this->_getCheckoutSession()->getQuoteId()) {
+            return true;
+        }
+
+        return $this->_customerSession->isLoggedIn()
+            && (int)$quote->getCustomerId() === (int)$this->_customerSession->getCustomerId();
+    }
+
     /**
      * @inheritdoc
      */