diff --git a/src/lib/Tests/UniversalDiscovery/Event/Subscriber/RichTextEmbedAllowedContentTypesTest.php b/src/lib/Tests/UniversalDiscovery/Event/Subscriber/RichTextEmbedAllowedContentTypesTest.php
new file mode 100644
index 0000000000..fbc83e1c37
--- /dev/null
+++ b/src/lib/Tests/UniversalDiscovery/Event/Subscriber/RichTextEmbedAllowedContentTypesTest.php
@@ -0,0 +1,142 @@
+<?php
+
+/**
+ * @copyright Copyright (C) eZ Systems AS. All rights reserved.
+ * @license For full copyright and license information view LICENSE file distributed with this source code.
+ */
+declare(strict_types=1);
+
+namespace EzSystems\EzPlatformAdminUi\Tests\UniversalDiscovery\Event\Subscriber;
+
+use eZ\Publish\API\Repository\ContentTypeService;
+use eZ\Publish\API\Repository\PermissionResolver;
+use eZ\Publish\API\Repository\Values\ContentType\ContentType;
+use eZ\Publish\API\Repository\Values\User\Limitation\ContentTypeLimitation;
+use EzSystems\EzPlatformAdminUi\Permission\PermissionCheckerInterface;
+use EzSystems\EzPlatformAdminUi\UniversalDiscovery\Event\ConfigResolveEvent;
+use EzSystems\EzPlatformAdminUi\UniversalDiscovery\Event\Subscriber\RichTextEmbedAllowedContentTypes;
+use PHPUnit\Framework\TestCase;
+
+final class RichTextEmbedAllowedContentTypesTest extends TestCase
+{
+    private const EXAMPLE_LIMITATIONS = [/* Some limitations */];
+
+    private const SUPPORTED_CONFIG_NAMES = ['richtext_embed', 'richtext_embed_image'];
+
+    private const ALLOWED_CONTENT_TYPES_IDS = [2, 4];
+    private const ALLOWED_CONTENT_TYPES = ['article', 'folder'];
+
+    /** @var \eZ\Publish\API\Repository\PermissionResolver|\PHPUnit\Framework\MockObject\MockObject */
+    private $permissionResolver;
+
+    /** @var \EzSystems\EzPlatformAdminUi\Permission\PermissionCheckerInterface|\PHPUnit\Framework\MockObject\MockObject */
+    private $permissionChecker;
+
+    /** @var \eZ\Publish\API\Repository\ContentTypeService|\PHPUnit\Framework\MockObject\MockObject */
+    private $contentTypeService;
+
+    /** @var \EzSystems\EzPlatformAdminUi\UniversalDiscovery\Event\Subscriber\RichTextEmbedAllowedContentTypes */
+    private $subscriber;
+
+    protected function setUp(): void
+    {
+        $this->permissionResolver = $this->createMock(PermissionResolver::class);
+        $this->permissionChecker = $this->createMock(PermissionCheckerInterface::class);
+        $this->contentTypeService = $this->createMock(ContentTypeService::class);
+
+        $this->subscriber = new RichTextEmbedAllowedContentTypes(
+            $this->permissionResolver,
+            $this->permissionChecker,
+            $this->contentTypeService
+        );
+    }
+
+    public function testUdwConfigResolveOnUnsupportedConfigName(): void
+    {
+        $this->permissionResolver->expects($this->never())->method('hasAccess');
+        $this->permissionChecker->expects($this->never())->method('getRestrictions');
+        $this->contentTypeService->expects($this->never())->method('loadContentTypeList');
+
+        $event = $this->createConfigResolveEvent('unsupported_config_name');
+
+        $this->subscriber->onUdwConfigResolve($event);
+
+        $this->assertEquals([], $event->getConfig());
+    }
+
+    /**
+     * @dataProvider dataProviderForUdwConfigResolveWhenThereIsNoContentReadLimitations
+     */
+    public function testUdwConfigResolveWhenThereIsNoContentReadLimitations(bool $hasAccess): void
+    {
+        $this->permissionResolver->method('hasAccess')->with('content', 'read')->willReturn($hasAccess);
+        $this->permissionChecker->expects($this->never())->method('getRestrictions');
+        $this->contentTypeService->expects($this->never())->method('loadContentTypeList');
+
+        $this->assertConfigurationResolvingResult([
+            'allowed_content_types' => null,
+        ]);
+    }
+
+    public function dataProviderForUdwConfigResolveWhenThereIsNoContentReadLimitations(): iterable
+    {
+        return [
+            ['hasAccess' => false],
+            ['hasAccess' => true],
+        ];
+    }
+
+    public function testUdwConfigResolveWhenThereAreContentReadLimitations(): void
+    {
+        $this->permissionResolver
+            ->method('hasAccess')
+            ->with('content', 'read')
+            ->willReturn(self::EXAMPLE_LIMITATIONS);
+
+        $this->permissionChecker
+            ->method('getRestrictions')
+            ->with(self::EXAMPLE_LIMITATIONS, ContentTypeLimitation::class)
+            ->willReturn(self::ALLOWED_CONTENT_TYPES_IDS);
+
+        $this->contentTypeService
+            ->method('loadContentTypeList')
+            ->with(self::ALLOWED_CONTENT_TYPES_IDS)
+            ->willReturn($this->createContentTypeListMock(self::ALLOWED_CONTENT_TYPES));
+
+        $this->assertConfigurationResolvingResult([
+            'allowed_content_types' => self::ALLOWED_CONTENT_TYPES,
+        ]);
+    }
+
+    private function assertConfigurationResolvingResult(?array $expectedConfiguration): void
+    {
+        foreach (self::SUPPORTED_CONFIG_NAMES as $configName) {
+            $event = $this->createConfigResolveEvent($configName);
+
+            $this->subscriber->onUdwConfigResolve($event);
+
+            $this->assertEquals(
+                $expectedConfiguration,
+                $event->getConfig()
+            );
+        }
+    }
+
+    private function createConfigResolveEvent(string $configName = 'richtext_embed'): ConfigResolveEvent
+    {
+        $event = new ConfigResolveEvent();
+        $event->setConfigName($configName);
+
+        return $event;
+    }
+
+    private function createContentTypeListMock(array $identifiers): array
+    {
+        return array_map(function (string $identifier) {
+            $contentType = $this->createMock(ContentType::class);
+            $contentType->method('__get')->with('identifier')->willReturn($identifier);
+
+            return $contentType;
+        }, $identifiers);
+    }
+}
diff --git a/src/lib/UniversalDiscovery/Event/ConfigResolveEvent.php b/src/lib/UniversalDiscovery/Event/ConfigResolveEvent.php
index 50a93665fa..c7ef8a62fd 100644
--- a/src/lib/UniversalDiscovery/Event/ConfigResolveEvent.php
+++ b/src/lib/UniversalDiscovery/Event/ConfigResolveEvent.php
@@ -12,16 +12,16 @@
 
 class ConfigResolveEvent extends Event
 {
-    const NAME = 'udw.resolve.config';
+    public const NAME = 'udw.resolve.config';
 
     /** @var string */
     protected $configName;
 
     /** @var array */
-    protected $config;
+    protected $config = [];
 
     /** @var array */
-    protected $context;
+    protected $context = [];
 
     /**
      * @return string
diff --git a/src/lib/UniversalDiscovery/Event/Subscriber/RichTextEmbedAllowedContentTypes.php b/src/lib/UniversalDiscovery/Event/Subscriber/RichTextEmbedAllowedContentTypes.php
index 03ae04e571..9d0083cc08 100644
--- a/src/lib/UniversalDiscovery/Event/Subscriber/RichTextEmbedAllowedContentTypes.php
+++ b/src/lib/UniversalDiscovery/Event/Subscriber/RichTextEmbedAllowedContentTypes.php
@@ -10,74 +10,60 @@
 
 use eZ\Publish\API\Repository\ContentTypeService;
 use eZ\Publish\API\Repository\PermissionResolver;
-use eZ\Publish\API\Repository\Values\ContentType\ContentType;
 use eZ\Publish\API\Repository\Values\User\Limitation\ContentTypeLimitation;
 use EzSystems\EzPlatformAdminUi\Permission\PermissionCheckerInterface;
 use EzSystems\EzPlatformAdminUi\UniversalDiscovery\Event\ConfigResolveEvent;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
-class RichTextEmbedAllowedContentTypes implements EventSubscriberInterface
+final class RichTextEmbedAllowedContentTypes implements EventSubscriberInterface
 {
-    /** @var string[] */
-    private $allowedContentTypesIdentifiers;
+    /** @var \eZ\Publish\API\Repository\PermissionResolver */
+    private $permissionResolver;
+
+    /** @var \EzSystems\EzPlatformAdminUi\Permission\PermissionCheckerInterface */
+    private $permissionChecker;
+
+    /** @var \eZ\Publish\API\Repository\ContentTypeService */
+    private $contentTypeService;
+
+    /** @var string[]|null */
+    private $allowedContentTypesIdentifiers = null;
 
-    /**
-     * @param \eZ\Publish\API\Repository\PermissionResolver $permissionResolver
-     * @param \EzSystems\EzPlatformAdminUi\Permission\PermissionCheckerInterface $permissionChecker
-     * @param \eZ\Publish\API\Repository\ContentTypeService $contentTypeService
-     *
-     * @throws \eZ\Publish\API\Repository\Exceptions\InvalidArgumentException
-     */
     public function __construct(
         PermissionResolver $permissionResolver,
         PermissionCheckerInterface $permissionChecker,
         ContentTypeService $contentTypeService
     ) {
-        $this->allowedContentTypesIdentifiers = $this->getAllowedContentTypesIdentifiers(
-            $permissionResolver,
-            $permissionChecker,
-            $contentTypeService
-        );
+        $this->permissionResolver = $permissionResolver;
+        $this->permissionChecker = $permissionChecker;
+        $this->contentTypeService = $contentTypeService;
     }
 
     /**
-     * @param \eZ\Publish\API\Repository\PermissionResolver $permissionResolver
-     * @param \EzSystems\EzPlatformAdminUi\Permission\PermissionCheckerInterface $permissionChecker
-     * @param \eZ\Publish\API\Repository\ContentTypeService $contentTypeService
-     *
      * @throws \eZ\Publish\API\Repository\Exceptions\InvalidArgumentException
      */
-    private function getAllowedContentTypesIdentifiers(
-        PermissionResolver $permissionResolver,
-        PermissionCheckerInterface $permissionChecker,
-        ContentTypeService $contentTypeService
-    ): array {
-        $access = $permissionResolver->hasAccess('content', 'read');
+    private function getAllowedContentTypesIdentifiers(): array
+    {
+        $access = $this->permissionResolver->hasAccess('content', 'read');
         if (!\is_array($access)) {
             return [];
         }
 
-        $restrictedContentTypesIds = $permissionChecker->getRestrictions($access, ContentTypeLimitation::class);
-
+        $restrictedContentTypesIds = $this->permissionChecker->getRestrictions($access, ContentTypeLimitation::class);
         if (empty($restrictedContentTypesIds)) {
             return [];
         }
 
-        $restrictedContentTypes = $contentTypeService->loadContentTypeList($restrictedContentTypesIds);
+        $allowedContentTypesIdentifiers = [];
+
+        $restrictedContentTypes = $this->contentTypeService->loadContentTypeList($restrictedContentTypesIds);
+        foreach ($restrictedContentTypes as $contentType) {
+            $allowedContentTypesIdentifiers[] = $contentType->identifier;
+        }
 
-        return array_values(
-            array_map(
-                static function (ContentType $contentType): string {
-                    return $contentType->identifier;
-                },
-                iterator_to_array($restrictedContentTypes)
-            )
-        );
+        return $allowedContentTypesIdentifiers;
     }
 
-    /**
-     * {@inheritdoc}
-     */
     public static function getSubscribedEvents(): array
     {
         return [
@@ -85,9 +71,6 @@ public static function getSubscribedEvents(): array
         ];
     }
 
-    /**
-     * @param \EzSystems\EzPlatformAdminUi\UniversalDiscovery\Event\ConfigResolveEvent $event
-     */
     public function onUdwConfigResolve(ConfigResolveEvent $event): void
     {
         $config = $event->getConfig();
@@ -96,7 +79,11 @@ public function onUdwConfigResolve(ConfigResolveEvent $event): void
             return;
         }
 
-        $config['allowed_content_types'] = !empty($this->allowedContentTypesIdentifiers) ? $this->restrictedContentTypesIdentifier : null;
+        if ($this->allowedContentTypesIdentifiers === null) {
+            $this->allowedContentTypesIdentifiers = $this->getAllowedContentTypesIdentifiers();
+        }
+
+        $config['allowed_content_types'] = !empty($this->allowedContentTypesIdentifiers) ? $this->allowedContentTypesIdentifiers : null;
 
         $event->setConfig($config);
     }