diff --git a/typo3/sysext/extbase/Classes/Configuration/ConfigurationManager.php b/typo3/sysext/extbase/Classes/Configuration/ConfigurationManager.php
index 4c25c4eaee71..5294c210258f 100644
--- a/typo3/sysext/extbase/Classes/Configuration/ConfigurationManager.php
+++ b/typo3/sysext/extbase/Classes/Configuration/ConfigurationManager.php
@@ -67,6 +67,7 @@ public function getContentObject(): ?ContentObjectRenderer
      * Note that this is a low level method and only makes sense to be used by Extbase internally.
      *
      * @param array $configuration The new configuration
+     * @internal
      */
     public function setConfiguration(array $configuration = []): void
     {
diff --git a/typo3/sysext/extbase/Classes/Configuration/ConfigurationManagerInterface.php b/typo3/sysext/extbase/Classes/Configuration/ConfigurationManagerInterface.php
index 9b1e79a24b00..be87d35b3c4f 100644
--- a/typo3/sysext/extbase/Classes/Configuration/ConfigurationManagerInterface.php
+++ b/typo3/sysext/extbase/Classes/Configuration/ConfigurationManagerInterface.php
@@ -55,6 +55,7 @@ public function getConfiguration(string $configurationType, ?string $extensionNa
      * Note that this is a low level method and only makes sense to be used by Extbase internally.
      *
      * @param array $configuration The new configuration
+     * @internal
      */
     public function setConfiguration(array $configuration = []): void;
 
diff --git a/typo3/sysext/extbase/Classes/ContentObject/ExtbasePluginContentObject.php b/typo3/sysext/extbase/Classes/ContentObject/ExtbasePluginContentObject.php
index 121866f7743d..088f3291faee 100644
--- a/typo3/sysext/extbase/Classes/ContentObject/ExtbasePluginContentObject.php
+++ b/typo3/sysext/extbase/Classes/ContentObject/ExtbasePluginContentObject.php
@@ -41,8 +41,8 @@ public function render($conf = [])
             // Come here only if we are not called from $TSFE->processNonCacheableContentPartsAndSubstituteContentMarkers()!
             $this->cObj->setUserObjectType(ContentObjectRenderer::OBJECTTYPE_USER);
         }
-        $extbaseBootstrap->initialize($conf);
-        $content = $extbaseBootstrap->handleFrontendRequest($this->request);
+        $request = $extbaseBootstrap->initialize($conf, $this->request);
+        $content = $extbaseBootstrap->handleFrontendRequest($request);
         // Rendering is deferred, as the action should not be cached, we pump this now to TSFE to be executed later-on
         if ($this->cObj->doConvertToUserIntObject) {
             $this->cObj->doConvertToUserIntObject = false;
diff --git a/typo3/sysext/extbase/Classes/Core/Bootstrap.php b/typo3/sysext/extbase/Classes/Core/Bootstrap.php
index 78d97d2a7e3b..aaca576c3aa0 100644
--- a/typo3/sysext/extbase/Classes/Core/Bootstrap.php
+++ b/typo3/sysext/extbase/Classes/Core/Bootstrap.php
@@ -79,14 +79,14 @@ public function setContentObjectRenderer(ContentObjectRenderer $cObj)
     /**
      * Explicitly initializes all necessary Extbase objects by invoking the various initialize* methods.
      *
-     * Usually this method is only called from unit tests or other applications which need a more fine grained control over
+     * Usually this method is only called from unit tests or other applications which need a more fine-grained control over
      * the initialization and request handling process. Most other applications just call the run() method.
      *
      * @param array $configuration The TS configuration array
      * @throws \RuntimeException
      * @see run()
      */
-    public function initialize(array $configuration): void
+    public function initialize(array $configuration, ServerRequestInterface $request): ServerRequestInterface
     {
         if (!Environment::isCli()) {
             if (!isset($configuration['extensionName']) || $configuration['extensionName'] === '') {
@@ -96,7 +96,7 @@ public function initialize(array $configuration): void
                 throw new \RuntimeException('Invalid configuration: "pluginName" is not set', 1290623027);
             }
         }
-        $this->initializeConfiguration($configuration);
+        return $this->initializeConfiguration($configuration, $request);
     }
 
     /**
@@ -105,11 +105,16 @@ public function initialize(array $configuration): void
      * @see initialize()
      * @internal
      */
-    public function initializeConfiguration(array $configuration): void
+    public function initializeConfiguration(array $configuration, ServerRequestInterface $request): ServerRequestInterface
     {
-        $this->cObj ??= $this->container->get(ContentObjectRenderer::class);
+        if ($this->cObj === null) {
+            $this->cObj = $this->container->get(ContentObjectRenderer::class);
+            $request = $request->withAttribute('currentContentObject', $this->cObj);
+        }
+        $this->cObj->setRequest($request);
         $this->configurationManager->setContentObject($this->cObj);
         $this->configurationManager->setConfiguration($configuration);
+        return $request;
         // todo: Shouldn't the configuration manager object – which is a singleton – be stateless?
         // todo: At this point we give the configuration manager a state, while we could directly pass the
         // todo: configuration (i.e. controllerName, actionName and such), directly to the request
@@ -133,7 +138,7 @@ public function initializeConfiguration(array $configuration): void
      */
     public function run(string $content, array $configuration, ServerRequestInterface $request): string
     {
-        $this->initialize($configuration);
+        $request = $this->initialize($configuration, $request);
         return $this->handleFrontendRequest($request);
     }
 
@@ -204,7 +209,6 @@ public function handleFrontendRequest(ServerRequestInterface $request): string
      *
      * Creates an Extbase Request, dispatches it and then returns the Response
      *
-     * @param ServerRequestInterface $request
      * @internal
      */
     public function handleBackendRequest(ServerRequestInterface $request): ResponseInterface
@@ -216,7 +220,7 @@ public function handleBackendRequest(ServerRequestInterface $request): ResponseI
             'pluginName' => $module?->getIdentifier(),
         ];
 
-        $this->initialize($configuration);
+        $request = $this->initialize($configuration, $request);
         $extbaseRequest = $this->extbaseRequestBuilder->build($request);
         $response = $this->dispatcher->dispatch($extbaseRequest);
         $this->resetSingletons();
diff --git a/typo3/sysext/extbase/Classes/Mvc/Web/Routing/UriBuilder.php b/typo3/sysext/extbase/Classes/Mvc/Web/Routing/UriBuilder.php
index 29f72e9974c9..b21216b825b9 100644
--- a/typo3/sysext/extbase/Classes/Mvc/Web/Routing/UriBuilder.php
+++ b/typo3/sysext/extbase/Classes/Mvc/Web/Routing/UriBuilder.php
@@ -40,22 +40,11 @@
  */
 class UriBuilder
 {
-    /**
-     * @var \TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface
-     */
-    protected $configurationManager;
+    protected ConfigurationManagerInterface $configurationManager;
 
-    /**
-     * @var \TYPO3\CMS\Extbase\Service\ExtensionService
-     */
-    protected $extensionService;
+    protected ExtensionService $extensionService;
 
-    /**
-     * An instance of \TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer
-     *
-     * @var \TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer
-     */
-    protected $contentObject;
+    protected ContentObjectRenderer $contentObject;
 
     protected ?RequestInterface $request = null;
 
@@ -147,16 +136,6 @@ public function injectExtensionService(ExtensionService $extensionService): void
         $this->extensionService = $extensionService;
     }
 
-    /**
-     * Life-cycle method that is called by the DI container as soon as this object is completely built
-     * @internal only to be used within Extbase, not part of TYPO3 Core API.
-     */
-    public function initializeObject(): void
-    {
-        $this->contentObject = $this->configurationManager->getContentObject()
-            ?? GeneralUtility::makeInstance(ContentObjectRenderer::class);
-    }
-
     /**
      * Sets the current request
      *
@@ -165,6 +144,15 @@ public function initializeObject(): void
     public function setRequest(RequestInterface $request): UriBuilder
     {
         $this->request = $request;
+        $contentObject = $request->getAttribute('currentContentObject');
+        if ($contentObject === null) {
+            // @todo: Review this. This should never be the case since extbase
+            //        bootstrap adds 'currentContentObject' to request. When this
+            //        if() kicks in, it most likely indicates an "out of scope" usage.
+            $contentObject = GeneralUtility::makeInstance(ContentObjectRenderer::class);
+            $contentObject->setRequest($request->withAttribute('currentContentObject', $contentObject));
+        }
+        $this->contentObject = $contentObject;
         return $this;
     }
 
@@ -478,7 +466,7 @@ public function reset(): UriBuilder
         /*
          * $this->request MUST NOT be reset here because the request is actually a hard dependency and not part
          * of the internal state of this object.
-         * todo: consider making the request a constructor dependency or get rid of it's usage
+         * todo: make the request a constructor dependency
          */
         return $this;
     }
diff --git a/typo3/sysext/extbase/Tests/Unit/Mvc/Web/Routing/UriBuilderTest.php b/typo3/sysext/extbase/Tests/Unit/Mvc/Web/Routing/UriBuilderTest.php
index a1743d08c9aa..e4ad44a0e1f0 100644
--- a/typo3/sysext/extbase/Tests/Unit/Mvc/Web/Routing/UriBuilderTest.php
+++ b/typo3/sysext/extbase/Tests/Unit/Mvc/Web/Routing/UriBuilderTest.php
@@ -73,7 +73,6 @@ protected function setUp(): void
         $this->subject->setRequest($this->mockRequest);
         $this->subject->injectConfigurationManager($this->createMock(ConfigurationManagerInterface::class));
         $this->subject->injectExtensionService($this->mockExtensionService);
-        $this->subject->initializeObject();
         $this->subject->_set('contentObject', $this->mockContentObject);
         $requestContextFactory = new RequestContextFactory(new BackendEntryPointResolver());
         $router = new Router($requestContextFactory);
diff --git a/typo3/sysext/extbase/Tests/UnitDeprecated/Mvc/Web/Routing/UriBuilderTest.php b/typo3/sysext/extbase/Tests/UnitDeprecated/Mvc/Web/Routing/UriBuilderTest.php
index 9492914d0012..d50addfc1993 100644
--- a/typo3/sysext/extbase/Tests/UnitDeprecated/Mvc/Web/Routing/UriBuilderTest.php
+++ b/typo3/sysext/extbase/Tests/UnitDeprecated/Mvc/Web/Routing/UriBuilderTest.php
@@ -41,7 +41,6 @@ protected function setUp(): void
         $this->subject->setRequest($this->createMock(Request::class));
         $this->subject->injectConfigurationManager($this->createMock(ConfigurationManagerInterface::class));
         $this->subject->injectExtensionService($this->mockExtensionService);
-        $this->subject->initializeObject();
         $this->subject->_set('contentObject', $this->createMock(ContentObjectRenderer::class));
     }
 
diff --git a/typo3/sysext/fluid/Classes/ViewHelpers/CObjectViewHelper.php b/typo3/sysext/fluid/Classes/ViewHelpers/CObjectViewHelper.php
index e814d8f25b90..4e3e2bb4a7eb 100644
--- a/typo3/sysext/fluid/Classes/ViewHelpers/CObjectViewHelper.php
+++ b/typo3/sysext/fluid/Classes/ViewHelpers/CObjectViewHelper.php
@@ -128,7 +128,7 @@ public static function renderStatic(array $arguments, \Closure $renderChildrenCl
         /** @var RenderingContext $renderingContext */
         $request = $renderingContext->getRequest();
         $contentObjectRenderer = self::getContentObjectRenderer($request);
-        $contentObjectRenderer->setRequest($request);
+        $contentObjectRenderer->setRequest($request->withAttribute('currentContentObject', $contentObjectRenderer));
         $tsfeBackup = null;
         if (!isset($GLOBALS['TSFE']) || !($GLOBALS['TSFE'] instanceof TypoScriptFrontendController)) {
             $tsfeBackup = self::simulateFrontendEnvironment();
diff --git a/typo3/sysext/form/Classes/Controller/FormFrontendController.php b/typo3/sysext/form/Classes/Controller/FormFrontendController.php
index 42f56fcddf6c..a331ad2f4862 100644
--- a/typo3/sysext/form/Classes/Controller/FormFrontendController.php
+++ b/typo3/sysext/form/Classes/Controller/FormFrontendController.php
@@ -69,7 +69,7 @@ public function renderAction(): ResponseInterface
             $formDefinition['persistenceIdentifier'] = $this->settings['persistenceIdentifier'];
             $formDefinition = $this->overrideByFlexFormSettings($formDefinition);
             $formDefinition = ArrayUtility::setValueByPath($formDefinition, 'renderingOptions._originalIdentifier', $formDefinition['identifier'], '.');
-            $formDefinition['identifier'] .= '-' . $this->configurationManager->getContentObject()->data['uid'];
+            $formDefinition['identifier'] .= '-' . $this->request->getAttribute('currentContentObject')->data['uid'];
         }
         $this->view->assign('formConfiguration', $formDefinition);
 
@@ -93,7 +93,7 @@ public function performAction(): ResponseInterface
      */
     protected function overrideByFlexFormSettings(array $formDefinition): array
     {
-        $flexFormData = GeneralUtility::xml2array($this->configurationManager->getContentObject()->data['pi_flexform'] ?? '');
+        $flexFormData = GeneralUtility::xml2array($this->request->getAttribute('currentContentObject')->data['pi_flexform'] ?? '');
 
         if (!is_array($flexFormData)) {
             return $formDefinition;
diff --git a/typo3/sysext/form/Classes/Domain/Finishers/ConfirmationFinisher.php b/typo3/sysext/form/Classes/Domain/Finishers/ConfirmationFinisher.php
index 4731641a98ad..9092fb5f36b2 100644
--- a/typo3/sysext/form/Classes/Domain/Finishers/ConfirmationFinisher.php
+++ b/typo3/sysext/form/Classes/Domain/Finishers/ConfirmationFinisher.php
@@ -57,20 +57,11 @@ class ConfirmationFinisher extends AbstractFinisher
         'typoscriptObjectPath' => 'lib.tx_form.contentElementRendering',
     ];
 
-    /**
-     * @var array
-     */
-    protected $typoScriptSetup = [];
+    protected array $typoScriptSetup = [];
 
-    /**
-     * @var ConfigurationManagerInterface
-     */
-    protected $configurationManager;
+    protected ConfigurationManagerInterface $configurationManager;
 
-    /**
-     * @var ContentObjectRenderer
-     */
-    protected $contentObjectRenderer;
+    protected ContentObjectRenderer $contentObjectRenderer;
 
     public function injectConfigurationManager(ConfigurationManagerInterface $configurationManager)
     {
@@ -109,7 +100,8 @@ protected function executeInternal()
                 }
                 $setup = $setup[$segment . '.'];
             }
-            $this->contentObjectRenderer->start([$contentElementUid], '');
+            $this->contentObjectRenderer->setRequest($this->finisherContext->getRequest());
+            $this->contentObjectRenderer->start([$contentElementUid]);
             $this->contentObjectRenderer->setCurrentVal((string)$contentElementUid);
             $message = $this->contentObjectRenderer->cObjGetSingle($setup[$lastSegment], $setup[$lastSegment . '.'], $lastSegment);
         } else {
diff --git a/typo3/sysext/form/Classes/Domain/Runtime/FormRuntime.php b/typo3/sysext/form/Classes/Domain/Runtime/FormRuntime.php
index 77c3508b59c3..4d0bf895210f 100644
--- a/typo3/sysext/form/Classes/Domain/Runtime/FormRuntime.php
+++ b/typo3/sysext/form/Classes/Domain/Runtime/FormRuntime.php
@@ -504,7 +504,7 @@ protected function isPostRequest(): bool
      */
     protected function isRenderedCached(): bool
     {
-        $contentObject = $this->configurationManager->getContentObject();
+        $contentObject = $this->request->getAttribute('currentContentObject');
         return $contentObject === null
             ? true
             // @todo this does not work when rendering a cached `FLUIDTEMPLATE` (not nested in `COA_INT`)
@@ -1079,8 +1079,8 @@ protected function getConditionResolver(): Resolver
         }
 
         $contentObjectData = [];
-        if ($this->configurationManager->getContentObject() instanceof ContentObjectRenderer) {
-            $contentObjectData = $this->configurationManager->getContentObject()->data;
+        if ($this->request->getAttribute('currentContentObject') instanceof ContentObjectRenderer) {
+            $contentObjectData = $this->request->getAttribute('currentContentObject')->data;
         }
 
         return GeneralUtility::makeInstance(
diff --git a/typo3/sysext/form/Tests/Functional/RequestHandling/Fixtures/Extensions/form_caching_tests/Classes/Controller/FormCachingTestsController.php b/typo3/sysext/form/Tests/Functional/RequestHandling/Fixtures/Extensions/form_caching_tests/Classes/Controller/FormCachingTestsController.php
index a5f24ffae29a..f613d10fc4af 100644
--- a/typo3/sysext/form/Tests/Functional/RequestHandling/Fixtures/Extensions/form_caching_tests/Classes/Controller/FormCachingTestsController.php
+++ b/typo3/sysext/form/Tests/Functional/RequestHandling/Fixtures/Extensions/form_caching_tests/Classes/Controller/FormCachingTestsController.php
@@ -24,14 +24,14 @@ class FormCachingTestsController extends ActionController
 {
     public function someRenderAction(): ResponseInterface
     {
-        $this->view->assign('formIdentifier', $this->request->getPluginName() . '-' . $this->configurationManager->getContentObject()->data['uid']);
+        $this->view->assign('formIdentifier', $this->request->getPluginName() . '-' . $this->request->getAttribute('currentContentObject')->data['uid']);
         $this->view->assign('pluginName', $this->request->getPluginName());
         return $this->htmlResponse();
     }
 
     public function somePerformAction(): ResponseInterface
     {
-        $this->view->assign('formIdentifier', $this->request->getPluginName() . '-' . $this->configurationManager->getContentObject()->data['uid']);
+        $this->view->assign('formIdentifier', $this->request->getPluginName() . '-' . $this->request->getAttribute('currentContentObject')->data['uid']);
         $this->view->assign('pluginName', $this->request->getPluginName());
         return $this->htmlResponse();
     }
diff --git a/typo3/sysext/form/Tests/Unit/Controller/FormFrontendControllerTest.php b/typo3/sysext/form/Tests/Unit/Controller/FormFrontendControllerTest.php
index bc6f8837f6c0..939b2372ba35 100644
--- a/typo3/sysext/form/Tests/Unit/Controller/FormFrontendControllerTest.php
+++ b/typo3/sysext/form/Tests/Unit/Controller/FormFrontendControllerTest.php
@@ -21,9 +21,11 @@
 use TYPO3\CMS\Core\Cache\CacheManager;
 use TYPO3\CMS\Core\Cache\Frontend\NullFrontend;
 use TYPO3\CMS\Core\Configuration\FlexForm\FlexFormTools;
+use TYPO3\CMS\Core\Http\ServerRequest;
 use TYPO3\CMS\Core\Tests\Unit\Fixtures\EventDispatcher\MockEventDispatcher;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
-use TYPO3\CMS\Extbase\Configuration\FrontendConfigurationManager;
+use TYPO3\CMS\Extbase\Mvc\ExtbaseRequestParameters;
+use TYPO3\CMS\Extbase\Mvc\Request;
 use TYPO3\CMS\Form\Controller\FormFrontendController;
 use TYPO3\CMS\Form\Domain\Configuration\ConfigurationService;
 use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
@@ -65,7 +67,12 @@ public function overrideByFlexFormSettingsReturnsNoOverriddenConfigurationIfFlex
         );
 
         $flexFormTools = new FlexFormTools(new MockEventDispatcher());
+        $request = (new ServerRequest())->withAttribute('extbase', new ExtbaseRequestParameters());
+        $request = (new Request($request));
         $contentObject = new ContentObjectRenderer();
+        $request = $request->withAttribute('currentContentObject', $contentObject);
+        $contentObject->setRequest($request);
+        $mockController->_set('request', $request);
         $contentObject->data = [
             'pi_flexform' => $flexFormTools->flexArray2Xml([
                 'data' => [
@@ -99,13 +106,6 @@ public function overrideByFlexFormSettingsReturnsNoOverriddenConfigurationIfFlex
             ]),
         ];
 
-        $frontendConfigurationManager = $this->createMock(FrontendConfigurationManager::class);
-        $frontendConfigurationManager
-            ->method('getContentObject')
-            ->willReturn($contentObject);
-
-        $mockController->_set('configurationManager', $frontendConfigurationManager);
-
         $configurationServiceMock->method('getPrototypeConfiguration')->with(self::anything())->willReturn([
             'finishersDefinition' => [
                 'EmailToReceiver' => [
@@ -196,7 +196,12 @@ public function overrideByFlexFormSettingsReturnsOverriddenConfigurationIfFlexfo
         );
 
         $flexFormTools = new FlexFormTools(new MockEventDispatcher());
+        $request = (new ServerRequest())->withAttribute('extbase', new ExtbaseRequestParameters());
+        $request = (new Request($request));
         $contentObject = new ContentObjectRenderer();
+        $request = $request->withAttribute('currentContentObject', $contentObject);
+        $contentObject->setRequest($request);
+        $mockController->_set('request', $request);
         $contentObject->data = [
             'pi_flexform' => $flexFormTools->flexArray2Xml([
                 'data' => [
@@ -230,13 +235,6 @@ public function overrideByFlexFormSettingsReturnsOverriddenConfigurationIfFlexfo
             ]),
         ];
 
-        $frontendConfigurationManager = $this->createMock(FrontendConfigurationManager::class);
-        $frontendConfigurationManager
-            ->method('getContentObject')
-            ->willReturn($contentObject);
-
-        $mockController->_set('configurationManager', $frontendConfigurationManager);
-
         $configurationServiceMock->method('getPrototypeConfiguration')->with(self::anything())->willReturn([
             'finishersDefinition' => [
                 'EmailToReceiver' => [
@@ -354,7 +352,12 @@ public function overrideByFlexFormSettingsReturnsNotOverriddenConfigurationKeyIf
         GeneralUtility::addInstance(FlexFormTools::class, new FlexFormTools($eventDispatcher));
 
         $flexFormTools = new FlexFormTools(new MockEventDispatcher());
+        $request = (new ServerRequest())->withAttribute('extbase', new ExtbaseRequestParameters());
+        $request = (new Request($request));
         $contentObject = new ContentObjectRenderer();
+        $request = $request->withAttribute('currentContentObject', $contentObject);
+        $contentObject->setRequest($request);
+        $mockController->_set('request', $request);
         $contentObject->data = [
             'pi_flexform' => $flexFormTools->flexArray2Xml([
                 'data' => [
@@ -388,13 +391,6 @@ public function overrideByFlexFormSettingsReturnsNotOverriddenConfigurationKeyIf
             ]),
         ];
 
-        $frontendConfigurationManager = $this->createMock(FrontendConfigurationManager::class);
-        $frontendConfigurationManager
-            ->method('getContentObject')
-            ->willReturn($contentObject);
-
-        $mockController->_set('configurationManager', $frontendConfigurationManager);
-
         $configurationServiceMock->method('getPrototypeConfiguration')->with(self::anything())->willReturn([
             'finishersDefinition' => [
                 'EmailToReceiver' => [
diff --git a/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php b/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php
index 76126deefcb7..bb361a8a44db 100644
--- a/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php
+++ b/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php
@@ -468,8 +468,7 @@ public function __wakeup()
         $this->container = GeneralUtility::getContainer();
 
         // We do not derive $this->request from globals here. The request is expected to be injected
-        // using setRequest() after deserialization or with start().
-        // (A fallback to $GLOBALS['TYPO3_REQUEST'] is available in getRequest() for BC)
+        // using setRequest(), a fallback to $GLOBALS['TYPO3_REQUEST'] is available in getRequest() for BC.
     }
 
     /**
@@ -5847,16 +5846,39 @@ protected function shallDebug(): bool
         return !empty($GLOBALS['TYPO3_CONF_VARS']['FE']['debug']);
     }
 
+    /**
+     * @todo: This getRequest() handling is pretty messy. We created a loop from
+     *        request to 'currentContentObject' back to request with this.
+     *        v13 should be refactored, probably with this patch chain:
+     *        * Remove fallback to $GLOBALS['TYPO3_REQUEST'] to force consumers
+     *          actually setting the request using setRequest().
+     *        * Protect this method.
+     *        * Get rid of public TSFE->cObj (the "page" instance of cObj).
+     *        * Avoid TSFE as constructor argument and make ContentObjectRenderer
+     *          free for DI, for instance to get the container injected.
+     *        * When getRequest() is protected or private, setRequest() should
+     *          *remove* the currentContentObject attribute again, to prevent
+     *          the object loop. This will work, since local getRequest() could
+     *          use $this when needed.
+     *
+     * @internal This method will be set to protected with TYPO3 v13.
+     */
     public function getRequest(): ServerRequestInterface
     {
         if ($this->request instanceof ServerRequestInterface) {
+            // Note attribute 'currentContentObject' has been set by setRequest() already.
             return $this->request;
         }
 
-        if (isset($GLOBALS['TYPO3_REQUEST']) && $GLOBALS['TYPO3_REQUEST'] instanceof ServerRequestInterface) {
-            return $GLOBALS['TYPO3_REQUEST'];
+        if (($GLOBALS['TYPO3_REQUEST'] ?? null) instanceof ServerRequestInterface) {
+            // @todo: We may want to deprecate this fallback and force consumers
+            //        to setRequest() after object instantiation / unserialization instead.
+            return $GLOBALS['TYPO3_REQUEST']->withAttribute('currentContentObject', $this);
         }
 
-        throw new ContentRenderingException('PSR-7 request is missing in ContentObjectRenderer. Inject with start(), setRequest() or provide via $GLOBALS[\'TYPO3_REQUEST\'].', 1607172972);
+        throw new ContentRenderingException(
+            'PSR-7 request is missing in ContentObjectRenderer. Inject with start(), setRequest() or provide via $GLOBALS[\'TYPO3_REQUEST\'].',
+            1607172972
+        );
     }
 }
diff --git a/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php b/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php
index 8dc8c92f6dcc..e009ba0bc96e 100644
--- a/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php
+++ b/typo3/sysext/frontend/Classes/Controller/TypoScriptFrontendController.php
@@ -2276,7 +2276,7 @@ protected function processNonCacheableContentPartsAndSubstituteContentMarkers(ar
                     $nonCacheableContent = '';
                     $contentObjectRendererForNonCacheable = unserialize($nonCacheableData[$nonCacheableKey]['cObj']);
                     /* @var ContentObjectRenderer $contentObjectRendererForNonCacheable */
-                    $contentObjectRendererForNonCacheable->setRequest($request);
+                    $contentObjectRendererForNonCacheable->setRequest($request->withAttribute('currentContentObject', $contentObjectRendererForNonCacheable));
                     switch ($nonCacheableData[$nonCacheableKey]['type']) {
                         case 'COA':
                             $nonCacheableContent = $contentObjectRendererForNonCacheable->cObjGetSingle('COA', $nonCacheableData[$nonCacheableKey]['conf']);
diff --git a/typo3/sysext/frontend/Classes/DataProcessing/FlexFormProcessor.php b/typo3/sysext/frontend/Classes/DataProcessing/FlexFormProcessor.php
index 830019b1f047..f9082c60373d 100644
--- a/typo3/sysext/frontend/Classes/DataProcessing/FlexFormProcessor.php
+++ b/typo3/sysext/frontend/Classes/DataProcessing/FlexFormProcessor.php
@@ -17,6 +17,7 @@
 
 namespace TYPO3\CMS\Frontend\DataProcessing;
 
+use Psr\Http\Message\ServerRequestInterface;
 use TYPO3\CMS\Core\Service\FlexFormService;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Frontend\ContentObject\ContentDataProcessor;
@@ -79,7 +80,9 @@ public function process(
         $targetVariableName = $cObj->stdWrapValue('as', $processorConfiguration, 'flexFormData');
 
         if (isset($processorConfiguration['dataProcessing.']) && is_array($processorConfiguration['dataProcessing.'])) {
-            $flexFormData = $this->processAdditionalDataProcessors($flexFormData, $processorConfiguration);
+            // @todo: It looks as if data processors should retrieve the current request from the outside,
+            //        this would avoid $cObj->getRequest() here.
+            $flexFormData = $this->processAdditionalDataProcessors($flexFormData, $processorConfiguration, $cObj->getRequest());
         }
 
         $processedData[$targetVariableName] = $flexFormData;
@@ -90,10 +93,11 @@ public function process(
     /**
      * Recursively process sub processors of a data processor
      */
-    public function processAdditionalDataProcessors(array $data, array $processorConfiguration): array
+    protected function processAdditionalDataProcessors(array $data, array $processorConfiguration, ServerRequestInterface $request): array
     {
         $contentObjectRenderer = GeneralUtility::makeInstance(ContentObjectRenderer::class);
-        $contentObjectRenderer->start([$data]);
+        $contentObjectRenderer->setRequest($request->withAttribute('currentContentObject', $contentObjectRenderer));
+        $contentObjectRenderer->start([$data], '');
         return GeneralUtility::makeInstance(ContentDataProcessor::class)->process(
             $contentObjectRenderer,
             $processorConfiguration,
diff --git a/typo3/sysext/frontend/Tests/Unit/ContentObject/CaseContentObjectTest.php b/typo3/sysext/frontend/Tests/Unit/ContentObject/CaseContentObjectTest.php
index 7041a175a936..95b64783ef13 100644
--- a/typo3/sysext/frontend/Tests/Unit/ContentObject/CaseContentObjectTest.php
+++ b/typo3/sysext/frontend/Tests/Unit/ContentObject/CaseContentObjectTest.php
@@ -43,6 +43,7 @@ protected function setUp(): void
 
         $request = new ServerRequest();
         $contentObjectRenderer = new ContentObjectRenderer($tsfe);
+        $request = $request->withAttribute('currentContentObject', $contentObjectRenderer);
         $contentObjectRenderer->setRequest($request);
         $cObjectFactoryMock = $this->getMockBuilder(ContentObjectFactory::class)->disableOriginalConstructor()->getMock();
 
@@ -51,7 +52,7 @@ protected function setUp(): void
         $caseContentObject->setContentObjectRenderer($contentObjectRenderer);
 
         $textContentObject = new TextContentObject();
-        $textContentObject->setRequest(new ServerRequest());
+        $textContentObject->setRequest($request);
         $textContentObject->setContentObjectRenderer($contentObjectRenderer);
 
         $cObjectFactoryMock->method('getContentObject')->willReturnMap([
diff --git a/typo3/sysext/frontend/Tests/Unit/DataProcessing/FlexFormProcessorTest.php b/typo3/sysext/frontend/Tests/Unit/DataProcessing/FlexFormProcessorTest.php
index 0c1f75771bb0..6763db6861a6 100644
--- a/typo3/sysext/frontend/Tests/Unit/DataProcessing/FlexFormProcessorTest.php
+++ b/typo3/sysext/frontend/Tests/Unit/DataProcessing/FlexFormProcessorTest.php
@@ -18,6 +18,7 @@
 namespace TYPO3\CMS\Frontend\Tests\Unit\DataProcessing;
 
 use PHPUnit\Framework\MockObject\MockObject;
+use TYPO3\CMS\Core\Http\ServerRequest;
 use TYPO3\CMS\Core\Service\FlexFormService;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Frontend\ContentObject\ContentDataProcessor;
@@ -204,6 +205,9 @@ public function subDataProcessorIsResolved(): void
             ],
         ];
         $this->contentObjectRendererMock->expects(self::once())->method('start')->with([$convertedFlexFormData]);
+        $request = new ServerRequest();
+        $request = $request->withAttribute('currentContentObject', $this->contentObjectRendererMock);
+        $this->contentObjectRendererMock->method('getRequest')->willReturn($request);
 
         $contentDataProcessorMock = $this->getMockBuilder(ContentDataProcessor::class)->disableOriginalConstructor()->getMock();
         $renderedDataFromProcessors = [