diff --git a/core/modules/media/src/Entity/Media.php b/core/modules/media/src/Entity/Media.php
index c21821077bcb23446f34ecaacccb236e8b90360d..d68a0a451c35b35c6e83f49a79ba4ab639de33f1 100644
--- a/core/modules/media/src/Entity/Media.php
+++ b/core/modules/media/src/Entity/Media.php
@@ -185,20 +185,11 @@ protected function updateThumbnail($from_queue = FALSE) {
     // Set the thumbnail alt.
     $media_source = $this->getSource();
     $plugin_definition = $media_source->getPluginDefinition();
+
+    $this->thumbnail->alt = '';
     if (!empty($plugin_definition['thumbnail_alt_metadata_attribute'])) {
       $this->thumbnail->alt = $media_source->getMetadata($this, $plugin_definition['thumbnail_alt_metadata_attribute']);
     }
-    else {
-      $this->thumbnail->alt = $this->t('Thumbnail', [], ['langcode' => $this->langcode->value]);
-    }
-
-    // Set the thumbnail title.
-    if (!empty($plugin_definition['thumbnail_title_metadata_attribute'])) {
-      $this->thumbnail->title = $media_source->getMetadata($this, $plugin_definition['thumbnail_title_metadata_attribute']);
-    }
-    else {
-      $this->thumbnail->title = $this->label();
-    }
 
     return $this;
   }
diff --git a/core/modules/media/src/Plugin/media/Source/Image.php b/core/modules/media/src/Plugin/media/Source/Image.php
index a83a5144d24b7416c27320330aac45730e25ceb4..34b565c05449af1df78e2b31e606816e6e32c43b 100644
--- a/core/modules/media/src/Plugin/media/Source/Image.php
+++ b/core/modules/media/src/Plugin/media/Source/Image.php
@@ -22,7 +22,8 @@
  *   label = @Translation("Image"),
  *   description = @Translation("Use local images for reusable media."),
  *   allowed_field_types = {"image"},
- *   default_thumbnail_filename = "no-thumbnail.png"
+ *   default_thumbnail_filename = "no-thumbnail.png",
+ *   thumbnail_alt_metadata_attribute = "thumbnail_alt_value"
  * )
  */
 class Image extends File {
@@ -138,6 +139,9 @@ public function getMetadata(MediaInterface $media, $name) {
 
       case 'thumbnail_uri':
         return $uri;
+
+      case 'thumbnail_alt_value':
+        return $media->get($this->configuration['source_field'])->alt ?: parent::getMetadata($media, $name);
     }
 
     return parent::getMetadata($media, $name);
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php b/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
index 85e4e5d7314470375e77a91e67d34281be9ff7b3..de352e001ac2019d94b777f8666e7978e27ad49e 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
@@ -167,13 +167,13 @@ protected function getExpectedNormalizedEntity() {
       ],
       'thumbnail' => [
         [
-          'alt' => 'Thumbnail',
+          'alt' => '',
           'width' => 180,
           'height' => 180,
           'target_id' => (int) $thumbnail->id(),
           'target_type' => 'file',
           'target_uuid' => $thumbnail->uuid(),
-          'title' => 'Llama',
+          'title' => NULL,
           'url' => $thumbnail->url(),
         ],
       ],
diff --git a/core/modules/media/tests/src/FunctionalJavascript/MediaSourceImageTest.php b/core/modules/media/tests/src/FunctionalJavascript/MediaSourceImageTest.php
index faf58c1a39b6d6753b61bc1ce16ee0d7c309bc26..cb013805ad278c528bbaa01385f806ff9fccc4e1 100644
--- a/core/modules/media/tests/src/FunctionalJavascript/MediaSourceImageTest.php
+++ b/core/modules/media/tests/src/FunctionalJavascript/MediaSourceImageTest.php
@@ -59,6 +59,8 @@ public function testMediaImageSource() {
 
     // Make sure the thumbnail is displayed from uploaded image.
     $assert_session->elementAttributeContains('css', '.image-style-thumbnail', 'src', 'example_1.jpeg');
+    // Ensure the thumbnail has the correct alt attribute.
+    $assert_session->elementAttributeContains('css', '.image-style-thumbnail', 'alt', 'Image Alt Text 1');
 
     // Load the media and check that all fields are properly populated.
     $media = Media::load(1);
diff --git a/core/modules/media/tests/src/Kernel/MediaSourceTest.php b/core/modules/media/tests/src/Kernel/MediaSourceTest.php
index 79cb7b41462f262c6f9ba295db946f7e9841a81b..ecf17785047e07786aa270aa5c031b2f6b68bc92 100644
--- a/core/modules/media/tests/src/Kernel/MediaSourceTest.php
+++ b/core/modules/media/tests/src/Kernel/MediaSourceTest.php
@@ -40,7 +40,6 @@ public function testSave() {
           'value' => 'Snowball',
         ],
         'thumbnail_uri' => [
-          'title' => 'Thumbnail',
           'value' => 'public://TheSisko.png',
         ],
       ]);
@@ -230,7 +229,7 @@ public function testThumbnail() {
 
     // Save a media item and make sure thumbnail was added.
     \Drupal::state()->set('media_source_test_attributes', [
-      'thumbnail_uri' => ['title' => 'Thumbnail', 'value' => 'public://thumbnail1.jpg'],
+      'thumbnail_uri' => ['value' => 'public://thumbnail1.jpg'],
     ]);
     /** @var \Drupal\media\MediaInterface $media */
     $media = Media::create([
@@ -242,45 +241,46 @@ public function testThumbnail() {
     $this->assertSame('public://thumbnail1.jpg', $media_source->getMetadata($media, 'thumbnail_uri'), 'Value of the thumbnail metadata attribute is not correct.');
     $media->save();
     $this->assertSame('public://thumbnail1.jpg', $media->thumbnail->entity->getFileUri(), 'Thumbnail was not added to the media item.');
-    $this->assertSame('Mr. Jones', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertEquals('Thumbnail', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    // We expect the title not to be present on the Thumbnail.
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('', $media->thumbnail->alt);
 
     // Now change the metadata attribute and make sure that the thumbnail stays
     // the same.
     \Drupal::state()->set('media_source_test_attributes', [
-      'thumbnail_uri' => ['title' => 'Thumbnail', 'value' => 'public://thumbnail2.jpg'],
+      'thumbnail_uri' => ['value' => 'public://thumbnail2.jpg'],
     ]);
     $this->assertSame('public://thumbnail2.jpg', $media_source->getMetadata($media, 'thumbnail_uri'), 'Value of the thumbnail metadata attribute is not correct.');
     $media->save();
     $this->assertSame('public://thumbnail1.jpg', $media->thumbnail->entity->getFileUri(), 'Thumbnail was not preserved.');
-    $this->assertSame('Mr. Jones', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertEquals('Thumbnail', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('', $media->thumbnail->alt);
 
     // Remove the thumbnail and make sure that it is auto-updated on save.
     $media->thumbnail->target_id = NULL;
     $this->assertSame('public://thumbnail2.jpg', $media_source->getMetadata($media, 'thumbnail_uri'), 'Value of the thumbnail metadata attribute is not correct.');
     $media->save();
     $this->assertSame('public://thumbnail2.jpg', $media->thumbnail->entity->getFileUri(), 'New thumbnail was not added to the media item.');
-    $this->assertSame('Mr. Jones', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertEquals('Thumbnail', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('', $media->thumbnail->alt);
 
     // Change the metadata attribute again, change the source field value too
     // and make sure that the thumbnail updates.
     \Drupal::state()->set('media_source_test_attributes', [
-      'thumbnail_uri' => ['title' => 'Thumbnail', 'value' => 'public://thumbnail1.jpg'],
+      'thumbnail_uri' => ['value' => 'public://thumbnail1.jpg'],
     ]);
     $media->field_media_test->value = 'some_new_value';
     $this->assertSame('public://thumbnail1.jpg', $media_source->getMetadata($media, 'thumbnail_uri'), 'Value of the thumbnail metadata attribute is not correct.');
     $media->save();
     $this->assertSame('public://thumbnail1.jpg', $media->thumbnail->entity->getFileUri(), 'New thumbnail was not added to the media item.');
-    $this->assertSame('Mr. Jones', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertEquals('Thumbnail', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('', $media->thumbnail->alt);
 
     // Change the thumbnail metadata attribute and make sure that the thumbnail
     // is set correctly.
     \Drupal::state()->set('media_source_test_attributes', [
-      'thumbnail_uri' => ['title' => 'Should not be used', 'value' => 'public://thumbnail1.jpg'],
-      'alternative_thumbnail_uri' => ['title' => 'Should be used', 'value' => 'public://thumbnail2.jpg'],
+      'thumbnail_uri' => ['value' => 'public://thumbnail1.jpg'],
+      'alternative_thumbnail_uri' => ['value' => 'public://thumbnail2.jpg'],
     ]);
     \Drupal::state()->set('media_source_test_definition', ['thumbnail_uri_metadata_attribute' => 'alternative_thumbnail_uri']);
     $media = Media::create([
@@ -293,14 +293,14 @@ public function testThumbnail() {
     $this->assertSame('public://thumbnail2.jpg', $media_source->getMetadata($media, 'alternative_thumbnail_uri'), 'Value of the thumbnail metadata attribute is not correct.');
     $media->save();
     $this->assertSame('public://thumbnail2.jpg', $media->thumbnail->entity->getFileUri(), 'Correct metadata attribute was not used for the thumbnail.');
-    $this->assertSame('Mr. Jones', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertEquals('Thumbnail', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('', $media->thumbnail->alt);
 
     // Enable queued thumbnails and make sure that the entity gets the default
     // thumbnail initially.
     \Drupal::state()->set('media_source_test_definition', []);
     \Drupal::state()->set('media_source_test_attributes', [
-      'thumbnail_uri' => ['title' => 'Should not be used', 'value' => 'public://thumbnail1.jpg'],
+      'thumbnail_uri' => ['value' => 'public://thumbnail1.jpg'],
     ]);
     $this->testMediaType->setQueueThumbnailDownloadsStatus(TRUE)->save();
     $media = Media::create([
@@ -311,8 +311,8 @@ public function testThumbnail() {
     $this->assertSame('public://thumbnail1.jpg', $media->getSource()->getMetadata($media, 'thumbnail_uri'), 'Value of the metadata attribute is not correct.');
     $media->save();
     $this->assertSame('public://media-icons/generic/generic.png', $media->thumbnail->entity->getFileUri(), 'Default thumbnail was not set initially.');
-    $this->assertSame('Mr. Jones', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertEquals('Thumbnail', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('', $media->thumbnail->alt);
 
     // Process the queue item and make sure that the thumbnail was updated too.
     $queue_name = 'media_entity_thumbnail';
@@ -330,18 +330,15 @@ public function testThumbnail() {
 
     $media = Media::load($media->id());
     $this->assertSame('public://thumbnail1.jpg', $media->thumbnail->entity->getFileUri(), 'Thumbnail was not updated by the queue.');
-    $this->assertSame('Mr. Jones', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertSame('Thumbnail', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('', $media->thumbnail->alt);
 
-    // Set alt and title metadata attributes and make sure they are used for the
-    // thumbnail.
+    // Set the alt metadata attribute and make sure it's used for the thumbnail.
     \Drupal::state()->set('media_source_test_definition', [
       'thumbnail_alt_metadata_attribute' => 'alt',
-      'thumbnail_title_metadata_attribute' => 'title',
     ]);
     \Drupal::state()->set('media_source_test_attributes', [
-      'alt' => ['title' => 'Alt text', 'value' => 'This will be alt.'],
-      'title' => ['title' => 'Title text', 'value' => 'This will be title.'],
+      'alt' => ['value' => 'This will be alt.'],
     ]);
     $media = Media::create([
       'bundle' => $this->testMediaType->id(),
@@ -350,8 +347,8 @@ public function testThumbnail() {
     ]);
     $media->save();
     $this->assertSame('Boxer', $media->getName(), 'Correct name was not set on the media item.');
-    $this->assertSame('This will be title.', $media->thumbnail->title, 'Title text was not set on the thumbnail.');
-    $this->assertSame('This will be alt.', $media->thumbnail->alt, 'Alt text was not set on the thumbnail.');
+    $this->assertEmpty($media->thumbnail->title);
+    $this->assertSame('This will be alt.', $media->thumbnail->alt);
   }
 
   /**
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php
index 33e0197e2f5412facc613852b1349132c0475baf..cf5d3da4f89f39d780a3f3dcda974dd8d4e9e1fb 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php
@@ -371,7 +371,7 @@ public function testMediaSource() {
     $values = $media_source->current()->getSource();
     $this->assertEquals(1, $values['mid']);
     $this->assertEquals('Foo media', $values['name'][0]['value']);
-    $this->assertEquals('Foo media', $values['thumbnail'][0]['title']);
+    $this->assertNull($values['thumbnail'][0]['title']);
     $this->assertEquals(1, $values['uid'][0]['target_id']);
     $this->assertEquals('image', $values['bundle'][0]['target_id']);
   }