diff --git a/core/modules/ckeditor/js/plugins/drupalimage/plugin.js b/core/modules/ckeditor/js/plugins/drupalimage/plugin.js
index 0f34691..029bc9e 100644
--- a/core/modules/ckeditor/js/plugins/drupalimage/plugin.js
+++ b/core/modules/ckeditor/js/plugins/drupalimage/plugin.js
@@ -305,7 +305,7 @@
             // @see Drupal.Ajax.prototype.beforeSerialize
             ajaxObject.beforeSerialize = function (element_settings, options) {
               formData.append('files[fid]', file);
-              $.each(this.$form.serializeArray(), function (k, v) {
+              this.$form.serializeArray().forEach(function (v) {
                 formData[v.name] = v.value;
                 formData.append(v.name, v.value);
               });
@@ -448,10 +448,10 @@
    */
   function getAjaxObject(id) {
     var ajaxInstance = null;
-    $.each(Drupal.ajax.instances, function (k, v) {
+    Drupal.ajax.instances.forEach(function (v, k) {
       if (v !== null && v.selector === id) {
         ajaxInstance = Drupal.ajax.instances[k];
-        return ajaxInstance;
+        return false;
       }
     });
     return ajaxInstance;
diff --git a/core/modules/ckeditor/tests/src/FunctionalJavascript/DrupalImageDragAndDropTest.php b/core/modules/ckeditor/tests/src/FunctionalJavascript/DrupalImageDragAndDropTest.php
new file mode 100644
index 0000000..f11d806
--- /dev/null
+++ b/core/modules/ckeditor/tests/src/FunctionalJavascript/DrupalImageDragAndDropTest.php
@@ -0,0 +1,107 @@
+<?php
+
+namespace Drupal\Tests\ckeditor\FunctionalJavascript;
+
+use Drupal\editor\Entity\Editor;
+use Drupal\filter\Entity\FilterFormat;
+use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
+
+/**
+ * Tests the JavaScript functionality of the DrupalImage drag-and-drop.
+ *
+ * @group ckeditor
+ */
+class DrupalImageDragAndDropTest extends JavascriptTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['editor', 'ckeditor', 'node'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    // Create text format, associate CKEditor.
+    $filtered_html_format = FilterFormat::create([
+      'format' => 'filtered_html',
+      'name' => 'Filtered HTML',
+      'weight' => 0,
+      'filters' => [],
+    ]);
+    $filtered_html_format->save();
+    $editor = Editor::create([
+      'format' => 'filtered_html',
+      'editor' => 'ckeditor',
+    ]);
+    $editor->save();
+
+    // Create node type.
+    $this->drupalCreateContentType(array(
+      'type' => 'article',
+      'name' => 'Article',
+    ));
+
+    $admin_user = $this->drupalCreateUser([
+      'create article content',
+      'edit any article content',
+      'use text format filtered_html',
+    ]);
+    $this->drupalLogin($admin_user);
+  }
+
+  /**
+   * Tests if an image can be uploaded via drag-and-drop in a CKEditor instance.
+   */
+  public function testDragAndDrop() {
+
+    $this->drupalGet('node/add/article');
+    $session = $this->getSession();
+    $page = $session->getPage();
+
+    $content = $page->find('css', '.cke_contents');
+    $this->assertTrue($content->isVisible(), 'CKEditor content area is visible.');
+
+    $javascript = <<<JS
+    (function(){
+      var byteCharacters = atob('R0lGODlhDgAOAIAAAAAAAP///yH5BAAAAAAALAAAAAAO' +
+       'AA4AAAIMhI+py+0Po5y02qsKADs=');
+      var byteNumbers = new Array(byteCharacters.length);
+      for (var i = 0; i < byteCharacters.length; i++) {
+        byteNumbers[i] = byteCharacters.charCodeAt(i);
+      }
+      var byteArray = new Uint8Array(byteNumbers);
+      var file = new Blob([byteArray], { type: 'image/gif' });
+      file.lastModifiedDate = new Date();
+      file.name = 'llama.gif';
+      var fileList = Array();
+      fileList.push(file);
+      var editor = CKEDITOR.instances['edit-body-0-value'];
+      var dataTransfer = new CKEDITOR.plugins.clipboard.dataTransfer({ files: fileList }, editor);
+      var data = {
+        dataValue: '',
+        method: 'drop',
+        dataTransfer: dataTransfer
+      };
+      editor.fire('paste', data, editor);
+      jQuery(window).one('editor:dialogopen', function (e, dialog) {
+        jQuery('[data-drupal-selector="edit-attributes-alt"]').val('Llama alt text');
+      });
+    }());
+JS;
+
+//    $asserted_session = $this->assertSession();
+//    $asserted_session->assertWaitOnAjaxRequest();
+    $session->executeScript($javascript);
+    // Click the submit button on the dialog
+    $session->executeScript("jQuery('.editor-image-dialog .js-form-submit').trigger('click');");
+    // Assert that the dialog has been closed.
+    $this->assertJsCondition("jQuery('.editor-drupal-dialog').length === 0", 5000);
+    // The dropped image should be visible inside the CKEditor instance.
+    $this->createScreenshot('public://screenshot.jpg');
+    $this->assertFileExists('public://screenshot.jpg');
+  }
+
+}