diff --git a/app/code/Magento/Catalog/Model/Api/SearchCriteria/CollectionProcessor/ConditionProcessor/ProductCategoryCondition.php b/app/code/Magento/Catalog/Model/Api/SearchCriteria/CollectionProcessor/ConditionProcessor/ProductCategoryCondition.php
index 09c3a3864bbc7..b11696ed0d129 100644
--- a/app/code/Magento/Catalog/Model/Api/SearchCriteria/CollectionProcessor/ConditionProcessor/ProductCategoryCondition.php
+++ b/app/code/Magento/Catalog/Model/Api/SearchCriteria/CollectionProcessor/ConditionProcessor/ProductCategoryCondition.php
@@ -102,7 +102,7 @@ private function getCategoryIds(Filter $filter): array
             }
         }
 
-        return array_unique(array_merge($categoryIds, ...$childCategoryIds));
+        return array_map('intval', array_unique(array_merge($categoryIds, ...$childCategoryIds)));
     }
 
     /**
diff --git a/app/code/Magento/Catalog/Model/ProductCategoryList.php b/app/code/Magento/Catalog/Model/ProductCategoryList.php
index 68d2c0606e567..f65d9b4c0bf7a 100644
--- a/app/code/Magento/Catalog/Model/ProductCategoryList.php
+++ b/app/code/Magento/Catalog/Model/ProductCategoryList.php
@@ -81,7 +81,10 @@ public function getCategoryIds($productId)
                 Select::SQL_UNION_ALL
             );
 
-            $this->categoryIdList[$productId] = $this->productResource->getConnection()->fetchCol($unionSelect);
+            $this->categoryIdList[$productId] = array_map(
+                'intval',
+                $this->productResource->getConnection()->fetchCol($unionSelect)
+            );
         }
 
         return $this->categoryIdList[$productId];
diff --git a/app/code/Magento/Catalog/Model/ResourceModel/Product/Collection.php b/app/code/Magento/Catalog/Model/ResourceModel/Product/Collection.php
index b131f78ad3b5c..83a8d36850573 100644
--- a/app/code/Magento/Catalog/Model/ResourceModel/Product/Collection.php
+++ b/app/code/Magento/Catalog/Model/ResourceModel/Product/Collection.php
@@ -1792,7 +1792,8 @@ protected function _productLimitationJoinWebsite()
             }
             $conditions[] = $this->getConnection()->quoteInto(
                 'product_website.website_id IN(?)',
-                $filters['website_ids']
+                $filters['website_ids'],
+                'int'
             );
         } elseif (isset(
             $filters['store_id']
@@ -1804,7 +1805,7 @@ protected function _productLimitationJoinWebsite()
         ) {
             $joinWebsite = true;
             $websiteId = $this->_storeManager->getStore($filters['store_id'])->getWebsiteId();
-            $conditions[] = $this->getConnection()->quoteInto('product_website.website_id = ?', $websiteId);
+            $conditions[] = $this->getConnection()->quoteInto('product_website.website_id = ?', $websiteId, 'int');
         }
 
         $fromPart = $this->getSelect()->getPart(\Magento\Framework\DB\Select::FROM);
@@ -2000,12 +2001,12 @@ protected function _applyProductLimitations()
 
         $conditions = [
             'cat_index.product_id=e.entity_id',
-            $this->getConnection()->quoteInto('cat_index.store_id=?', $filters['store_id']),
+            $this->getConnection()->quoteInto('cat_index.store_id=?', $filters['store_id'], 'int'),
         ];
         if (isset($filters['visibility']) && !isset($filters['store_table'])) {
-            $conditions[] = $this->getConnection()->quoteInto('cat_index.visibility IN(?)', $filters['visibility']);
+            $conditions[] = $this->getConnection()->quoteInto('cat_index.visibility IN(?)', $filters['visibility'], 'int');
         }
-        $conditions[] = $this->getConnection()->quoteInto('cat_index.category_id=?', $filters['category_id']);
+        $conditions[] = $this->getConnection()->quoteInto('cat_index.category_id=?', $filters['category_id'], 'int');
         if (isset($filters['category_is_anchor'])) {
             $conditions[] = $this->getConnection()->quoteInto('cat_index.is_parent=?', $filters['category_is_anchor']);
         }
diff --git a/lib/internal/Magento/Framework/Mview/View.php b/lib/internal/Magento/Framework/Mview/View.php
index 1f1bde6bb021c..fca827ca2505f 100644
--- a/lib/internal/Magento/Framework/Mview/View.php
+++ b/lib/internal/Magento/Framework/Mview/View.php
@@ -285,7 +285,7 @@ public function update()
                 for ($versionFrom = $lastVersionId; $versionFrom < $currentVersionId; $versionFrom += $versionBatchSize) {
                     // Don't go past the current version for atomicy.
                     $versionTo = min($currentVersionId, $versionFrom + $versionBatchSize);
-                    $ids = $this->getChangelog()->getList($versionFrom, $versionTo);
+                    $ids = array_map('intval', $this->getChangelog()->getList($versionFrom, $versionTo));
 
                     // We run the actual indexer in batches.  Chunked AFTER loading to avoid duplicates in separate chunks.
                     $chunks = array_chunk($ids, $batchSize);