diff -Nuar a/vendor/magento/module-shared-catalog/Plugin/Quote/Api/ValidateAddProductToCartPlugin.php b/vendor/magento/module-shared-catalog/Plugin/Quote/Api/ValidateAddProductToCartPlugin.php
index cf50d683e..15d0f7e1f 100644
--- a/vendor/magento/module-shared-catalog/Plugin/Quote/Api/ValidateAddProductToCartPlugin.php
+++ b/vendor/magento/module-shared-catalog/Plugin/Quote/Api/ValidateAddProductToCartPlugin.php
@@ -5,7 +5,17 @@
  */
 namespace Magento\SharedCatalog\Plugin\Quote\Api;
 
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Quote\Api\CartItemRepositoryInterface;
+use Magento\Quote\Api\CartRepositoryInterface;
+use Magento\Quote\Api\Data\CartItemInterface;
+use Magento\SharedCatalog\Api\Data\SharedCatalogInterface;
+use Magento\SharedCatalog\Api\ProductManagementInterface;
+use Magento\SharedCatalog\Api\SharedCatalogManagementInterface;
+use Magento\SharedCatalog\Api\StatusInfoInterface;
+use Magento\SharedCatalog\Model\SharedCatalogLocator;
 use Magento\Store\Model\ScopeInterface;
+use Magento\Store\Model\StoreManagerInterface;
 
 /**
  * Denies to add product to cart if SharedCatalog module is active and product is not in a shared catalog.
@@ -13,50 +23,50 @@ use Magento\Store\Model\ScopeInterface;
 class ValidateAddProductToCartPlugin
 {
     /**
-     * @var \Magento\SharedCatalog\Api\StatusInfoInterface
+     * @var StatusInfoInterface
      */
     private $moduleConfig;
 
     /**
-     * @var \Magento\Quote\Api\CartRepositoryInterface
+     * @var CartRepositoryInterface
      */
     private $quoteRepository;
 
     /**
-     * @var \Magento\SharedCatalog\Model\SharedCatalogLocator
+     * @var SharedCatalogLocator
      */
     private $sharedCatalogLocator;
 
     /**
-     * @var \Magento\SharedCatalog\Api\SharedCatalogManagementInterface
+     * @var SharedCatalogManagementInterface
      */
     private $sharedCatalogManagement;
 
     /**
-     * @var \Magento\SharedCatalog\Api\ProductManagementInterface
+     * @var ProductManagementInterface
      */
     private $sharedCatalogProductManagement;
 
     /**
-     * @var \Magento\Store\Model\StoreManagerInterface
+     * @var StoreManagerInterface
      */
     private $storeManager;
 
     /**
-     * @param \Magento\SharedCatalog\Api\StatusInfoInterface $moduleConfig
-     * @param \Magento\Quote\Api\CartRepositoryInterface $quoteRepository
-     * @param \Magento\SharedCatalog\Model\SharedCatalogLocator $sharedCatalogLocator
-     * @param \Magento\SharedCatalog\Api\SharedCatalogManagementInterface $sharedCatalogManagement
-     * @param \Magento\SharedCatalog\Api\ProductManagementInterface $sharedCatalogProductManagement
-     * @param \Magento\Store\Model\StoreManagerInterface $storeManager
+     * @param StatusInfoInterface $moduleConfig
+     * @param CartRepositoryInterface $quoteRepository
+     * @param SharedCatalogLocator $sharedCatalogLocator
+     * @param SharedCatalogManagementInterface $sharedCatalogManagement
+     * @param ProductManagementInterface $sharedCatalogProductManagement
+     * @param StoreManagerInterface $storeManager
      */
     public function __construct(
-        \Magento\SharedCatalog\Api\StatusInfoInterface $moduleConfig,
-        \Magento\Quote\Api\CartRepositoryInterface $quoteRepository,
-        \Magento\SharedCatalog\Model\SharedCatalogLocator $sharedCatalogLocator,
-        \Magento\SharedCatalog\Api\SharedCatalogManagementInterface $sharedCatalogManagement,
-        \Magento\SharedCatalog\Api\ProductManagementInterface $sharedCatalogProductManagement,
-        \Magento\Store\Model\StoreManagerInterface $storeManager
+        StatusInfoInterface $moduleConfig,
+        CartRepositoryInterface $quoteRepository,
+        SharedCatalogLocator $sharedCatalogLocator,
+        SharedCatalogManagementInterface $sharedCatalogManagement,
+        ProductManagementInterface $sharedCatalogProductManagement,
+        StoreManagerInterface $storeManager
     ) {
         $this->moduleConfig = $moduleConfig;
         $this->quoteRepository = $quoteRepository;
@@ -69,26 +79,30 @@ class ValidateAddProductToCartPlugin
     /**
      * Denies to add product to cart if SharedCatalog module is active and product is not in a shared catalog.
      *
-     * @param \Magento\Quote\Api\CartItemRepositoryInterface $subject
-     * @param \Magento\Quote\Api\Data\CartItemInterface $cartItem
+     * @param CartItemRepositoryInterface $subject
+     * @param CartItemInterface $cartItem
      * @return array
-     * @throws \Magento\Framework\Exception\NoSuchEntityException
+     * @throws NoSuchEntityException
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
     public function beforeSave(
-        \Magento\Quote\Api\CartItemRepositoryInterface $subject,
-        \Magento\Quote\Api\Data\CartItemInterface $cartItem
+        CartItemRepositoryInterface $subject,
+        CartItemInterface $cartItem
     ) {
         $website = $this->storeManager->getWebsite()->getId();
         if ($this->moduleConfig->isActive(ScopeInterface::SCOPE_WEBSITE, $website)) {
             $quote = $this->quoteRepository->get($cartItem->getQuoteId());
-            $sharedCatalog = $this->getSharedCatalog($quote->getCustomerGroupId());
             $sku = $cartItem->getSku();
 
-            if (!$sharedCatalog || !$this->isProductInSharedCatalog($sharedCatalog->getId(), $sku)) {
-                throw new \Magento\Framework\Exception\NoSuchEntityException(
-                    __('Requested product doesn\'t exist: %1.', $sku)
-                );
+            if (!$this->isProductInPublicCatalog($sku)) {
+
+                $sharedCatalog = $this->getSharedCatalog($quote->getCustomerGroupId());
+
+                if (!$sharedCatalog || !$this->isProductInSharedCatalog($sharedCatalog->getId(), $sku)) {
+                    throw new NoSuchEntityException(
+                        __('Requested product doesn\'t exist: %1.', $sku)
+                    );
+                }
             }
         }
 
@@ -99,7 +113,7 @@ class ValidateAddProductToCartPlugin
      * Get shared catalog by customer group id if $customerGroupId is not empty or load public shared catalog.
      *
      * @param int $customerGroupId
-     * @return \Magento\SharedCatalog\Api\Data\SharedCatalogInterface|null
+     * @return SharedCatalogInterface|null
      */
     private function getSharedCatalog($customerGroupId)
     {
@@ -123,4 +137,21 @@ class ValidateAddProductToCartPlugin
 
         return in_array($sku, $productSkus);
     }
+
+    /**
+     * Is a product with a given sku assigned to a public catalog
+     *
+     * @param string $sku
+     * @return bool
+     */
+    private function isProductInPublicCatalog($sku): bool
+    {
+        if (!$this->sharedCatalogManagement->isPublicCatalogExist()) {
+            return false;
+        }
+        $publicCatalog = $this->sharedCatalogManagement->getPublicCatalog();
+        $productSkus = $this->sharedCatalogProductManagement->getProducts($publicCatalog->getId());
+
+        return in_array($sku, $productSkus);
+    }
 }