diff --git a/Classes/ContentObject/JsonContentContentObject.php b/Classes/ContentObject/JsonContentContentObject.php
index 3304abeb..1427e82e 100755
--- a/Classes/ContentObject/JsonContentContentObject.php
+++ b/Classes/ContentObject/JsonContentContentObject.php
@@ -150,7 +150,7 @@ public function render($conf = []): string
     /**
      * @param array<string, mixed> $contentElements
      * @param array<string, mixed> $conf
-     * @return array<string,<array<int, mixed>>
+     * @return array<string, array<int, mixed>>
      */
     protected function groupContentElementsByColPos(array $contentElements, array $conf): array
     {
@@ -167,11 +167,12 @@ protected function groupContentElementsByColPos(array $contentElements, array $c
                 $element = $this->headlessUserInt->wrap($element);
             }
 
-            $element = json_decode($element, true);
+            $decoded = json_decode($element, true);
 
-            if ($element === []) {
+            if (!is_array($decoded) || $decoded === []) {
                 continue;
             }
+            $element = $decoded;
 
             $colPos = $this->getColPosFromElement($groupingEnabled, $element);
 
@@ -184,11 +185,14 @@ protected function groupContentElementsByColPos(array $contentElements, array $c
 
         if ($groupingEnabled && $this->isSortByBackendLayoutEnabled($conf)) {
             $backendLayoutView = GeneralUtility::makeInstance(BackendLayoutView::class);
-            $backendLayout = $backendLayoutView->getSelectedBackendLayout($this->request->getAttribute('routing')->getPageId());
+            $routing = $this->request->getAttribute('routing');
+            $backendLayout = $routing !== null
+                ? $backendLayoutView->getSelectedBackendLayout($routing->getPageId())
+                : null;
 
             $sorted = [];
             foreach ($backendLayout['__colPosList'] ?? [] as $value) {
-                $sorted['colPos' . $value] = $data['colPos' . $value];
+                $sorted['colPos' . $value] = $data['colPos' . $value] ?? [];
             }
 
             $data = $sorted;
diff --git a/Classes/ContentObject/JsonContentObject.php b/Classes/ContentObject/JsonContentObject.php
index ff08a25d..3691c55f 100755
--- a/Classes/ContentObject/JsonContentObject.php
+++ b/Classes/ContentObject/JsonContentObject.php
@@ -46,16 +46,16 @@ public function __construct(
      */
     public function render($conf = []): string
     {
+        if (!is_array($conf)) {
+            $conf = [];
+        }
+
         if (!empty($conf['if.']) && !$this->cObj->checkIf($conf['if.'])) {
             return '';
         }
 
         $data = [];
 
-        if (!is_array($conf)) {
-            $conf = [];
-        }
-
         $this->conf = $conf;
 
         if (isset($conf['fields.'])) {
diff --git a/Classes/DataProcessing/DataProcessingTrait.php b/Classes/DataProcessing/DataProcessingTrait.php
index 844cbd4a..5800d76f 100644
--- a/Classes/DataProcessing/DataProcessingTrait.php
+++ b/Classes/DataProcessing/DataProcessingTrait.php
@@ -42,7 +42,7 @@ protected function removeDataIfnotAppendInConfiguration(array $processorConfigur
 
     protected function isMenuProcessor(): bool
     {
-        return __CLASS__ === MenuProcessor::class;
+        return $this instanceof MenuProcessor;
     }
 
     /**
diff --git a/Classes/DataProcessing/ExtractPropertyProcessor.php b/Classes/DataProcessing/ExtractPropertyProcessor.php
index 6ce1bd28..9730d3c3 100644
--- a/Classes/DataProcessing/ExtractPropertyProcessor.php
+++ b/Classes/DataProcessing/ExtractPropertyProcessor.php
@@ -64,13 +64,17 @@ public function process(
 
         $key = GeneralUtility::trimExplode('.', $processorConfiguration['key'], true);
 
-        // Extract (nested) property
-        do {
-            $processedData = $processedData[array_shift($key)] ?? null;
-        } while (count($key));
+        $value = $processedData;
+        foreach ($key as $segment) {
+            if (!is_array($value)) {
+                $value = null;
+                break;
+            }
+            $value = $value[$segment] ?? null;
+        }
 
         return [
-            $targetFieldName => $processedData,
+            $targetFieldName => $value,
         ];
     }
 }
diff --git a/Classes/DataProcessing/FilesProcessor.php b/Classes/DataProcessing/FilesProcessor.php
index 33d3e6a3..2be5da9b 100644
--- a/Classes/DataProcessing/FilesProcessor.php
+++ b/Classes/DataProcessing/FilesProcessor.php
@@ -93,12 +93,27 @@ public function process(
             $this->defaults['as']
         );
 
+        if (!$this->hasFileSources($processorConfiguration)) {
+            $processedData[$targetFieldName] = [];
+            return $this->removeDataIfnotAppendInConfiguration($processorConfiguration, $processedData);
+        }
+
         $this->fileObjects = $this->fetchData();
         $processedData[$targetFieldName] = $this->processFiles($properties);
 
         return $this->removeDataIfnotAppendInConfiguration($processorConfiguration, $processedData);
     }
 
+    private function hasFileSources(array $processorConfiguration): bool
+    {
+        foreach (['references', 'references.', 'files', 'files.', 'collections', 'collections.', 'folders', 'folders.'] as $key) {
+            if (!empty($processorConfiguration[$key])) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     /**
      * @return array
      */
diff --git a/Classes/DataProcessing/RootSiteProcessing/DomainSchema.php b/Classes/DataProcessing/RootSiteProcessing/DomainSchema.php
index 8a8d5336..117f34b6 100644
--- a/Classes/DataProcessing/RootSiteProcessing/DomainSchema.php
+++ b/Classes/DataProcessing/RootSiteProcessing/DomainSchema.php
@@ -43,9 +43,10 @@ public function process(SiteProviderInterface $provider, array $options = []): a
         $result = [];
 
         foreach ($provider->getSites() as $site) {
+            $urlUtility = $this->urlUtility->withSite($site);
             $protocol = $site->getBase()->getScheme() . '://';
             $baseUrl = $protocol . $site->getBase()->getHost();
-            $url = $this->urlUtility->getFrontendUrlForPage($baseUrl, $site->getRootPageId());
+            $url = $urlUtility->getFrontendUrlForPage($baseUrl, $site->getRootPageId());
 
             $locales = [];
 
@@ -57,7 +58,7 @@ public function process(SiteProviderInterface $provider, array $options = []): a
                 'name' => str_replace($protocol, '', $url),
                 'baseURL' => $url,
                 'api' => [
-                    'baseURL' => $this->urlUtility->getProxyUrl(),
+                    'baseURL' => $urlUtility->getProxyUrl(),
                 ],
                 'i18n' => [
                     'locales' => $locales,
diff --git a/Classes/DataProcessing/RootSiteProcessing/SiteProvider.php b/Classes/DataProcessing/RootSiteProcessing/SiteProvider.php
index 2a907587..e5a25b33 100644
--- a/Classes/DataProcessing/RootSiteProcessing/SiteProvider.php
+++ b/Classes/DataProcessing/RootSiteProcessing/SiteProvider.php
@@ -81,10 +81,8 @@ public function prepare(array $config, int $siteUid): self
             $sorting = GeneralUtility::makeInstance($customSorting, $sites, $pages, $sortingField);
             $sites = $sorting->sort();
         } else {
-            usort($sites, static function (Site $siteA, Site $siteB) use ($pages, $sortingField) {
-                // phpcs:ignore Generic.Files.LineLength
-                return (int)$pages[$siteA->getRootPageId()][$sortingField] >= (int)$pages[$siteB->getRootPageId()][$sortingField] ? 1 : -1;
-            });
+            usort($sites, static fn(Site $siteA, Site $siteB): int =>
+                (int)$pages[$siteA->getRootPageId()][$sortingField] <=> (int)$pages[$siteB->getRootPageId()][$sortingField]);
         }
 
         $this->sites = $sites;
diff --git a/Classes/Event/Listener/AfterLinkIsGeneratedListener.php b/Classes/Event/Listener/AfterLinkIsGeneratedListener.php
index a1a09424..1a0739b3 100644
--- a/Classes/Event/Listener/AfterLinkIsGeneratedListener.php
+++ b/Classes/Event/Listener/AfterLinkIsGeneratedListener.php
@@ -182,16 +182,16 @@ private function resolveTypolinkParameterString(string $mixedLinkParameter, arra
         )) {
             // Disallow insecure scheme's like javascript: or data:
             throw new UnableToLinkException(
-                'Insuecure scheme for linking detected with "' . $mixedLinkParameter . "'",
+                'Insecure scheme for linking detected with "' . $mixedLinkParameter . "'",
                 1641986533
             );
         }
 
         // additional parameters that need to be set
         if (($linkParameterParts['additionalParams'] ?? '') !== '') {
-            $forceParams = $linkParameterParts['additionalParams'];
-            // params value
-            $linkConfiguration['additionalParams'] = ($linkConfiguration['additionalParams'] ?? '') . $forceParams[0] === '&' ? $forceParams : '&' . $forceParams;
+            $forceParams = (string)$linkParameterParts['additionalParams'];
+            $prefix = $forceParams[0] === '&' ? '' : '&';
+            $linkConfiguration['additionalParams'] = ($linkConfiguration['additionalParams'] ?? '') . $prefix . $forceParams;
         }
 
         return [
diff --git a/Classes/Event/Listener/RedirectUrlAdditionalParamsListener.php b/Classes/Event/Listener/RedirectUrlAdditionalParamsListener.php
index 9027ddfc..00d35b26 100644
--- a/Classes/Event/Listener/RedirectUrlAdditionalParamsListener.php
+++ b/Classes/Event/Listener/RedirectUrlAdditionalParamsListener.php
@@ -27,7 +27,8 @@
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 
 use function parse_str;
-use function strpos;
+use function parse_url;
+use function str_contains;
 
 class RedirectUrlAdditionalParamsListener implements LoggerAwareInterface
 {
@@ -61,14 +62,16 @@ public function __invoke(RedirectUrlEvent $event): void
         );
         $redirectTarget = $linkParameterParts['url'] ?? '';
         $linkDetails = $this->resolveLinkDetailsFromLinkTarget($redirectTarget);
+        $additionalParams = (string)($linkParameterParts['additionalParams'] ?? '');
 
-        if (($linkDetails['type'] === LinkService::TYPE_PAGE) &&
-            strpos($linkParameterParts['additionalParams'], '[action]=') > 0 &&
-            strpos($linkParameterParts['additionalParams'], '[controller]=') > 0) {
+        if (($linkDetails['type'] ?? null) === LinkService::TYPE_PAGE &&
+            str_contains($additionalParams, '[action]=') &&
+            str_contains($additionalParams, '[controller]=')) {
             try {
                 $site = $request->getAttribute('site');
-                parse_str($linkParameterParts['url'], $typolinkData);
-                parse_str($linkParameterParts['additionalParams'], $params);
+                $urlQuery = parse_url((string)($linkParameterParts['url'] ?? ''), PHP_URL_QUERY) ?? '';
+                parse_str($urlQuery, $typolinkData);
+                parse_str($additionalParams, $params);
 
                 $languageId = isset($typolinkData['L']) ? (int)$typolinkData['L'] : 0;
 
diff --git a/Classes/Resource/Rendering/AudioTagRenderer.php b/Classes/Resource/Rendering/AudioTagRenderer.php
index 295e5bc0..8d450270 100644
--- a/Classes/Resource/Rendering/AudioTagRenderer.php
+++ b/Classes/Resource/Rendering/AudioTagRenderer.php
@@ -22,6 +22,8 @@
  */
 class AudioTagRenderer extends \TYPO3\CMS\Core\Resource\Rendering\AudioTagRenderer
 {
+    private ?FileUtility $fileUtility = null;
+
     public function getPriority(): int
     {
         return 2;
@@ -39,7 +41,8 @@ public function getPriority(): int
     public function render(FileInterface $file, $width, $height, array $options = []): string
     {
         if (($options['returnUrl'] ?? false) === true) {
-            return htmlspecialchars(GeneralUtility::makeInstance(FileUtility::class)->getAbsoluteUrl($file->getPublicUrl()), ENT_QUOTES | ENT_HTML5);
+            $fileUtility = $this->fileUtility ??= GeneralUtility::makeInstance(FileUtility::class);
+            return htmlspecialchars($fileUtility->getAbsoluteUrl($file->getPublicUrl()), ENT_QUOTES | ENT_HTML5);
         }
         return parent::render(...func_get_args());
     }
diff --git a/Classes/Resource/Rendering/VideoTagRenderer.php b/Classes/Resource/Rendering/VideoTagRenderer.php
index 7aea3e23..b93df99f 100644
--- a/Classes/Resource/Rendering/VideoTagRenderer.php
+++ b/Classes/Resource/Rendering/VideoTagRenderer.php
@@ -22,6 +22,8 @@
  */
 class VideoTagRenderer extends \TYPO3\CMS\Core\Resource\Rendering\VideoTagRenderer
 {
+    private ?FileUtility $fileUtility = null;
+
     public function getPriority(): int
     {
         return 2;
@@ -40,7 +42,8 @@ public function getPriority(): int
     public function render(FileInterface $file, $width, $height, array $options = []): string
     {
         if (($options['returnUrl'] ?? false) === true) {
-            return htmlspecialchars(GeneralUtility::makeInstance(FileUtility::class)->getAbsoluteUrl($file->getPublicUrl()), ENT_QUOTES | ENT_HTML5);
+            $fileUtility = $this->fileUtility ??= GeneralUtility::makeInstance(FileUtility::class);
+            return htmlspecialchars($fileUtility->getAbsoluteUrl($file->getPublicUrl()), ENT_QUOTES | ENT_HTML5);
         }
         return parent::render(...func_get_args());
     }
diff --git a/Classes/Seo/MetaTag/AbstractMetaTagManager.php b/Classes/Seo/MetaTag/AbstractMetaTagManager.php
index 0a540545..0601eab1 100644
--- a/Classes/Seo/MetaTag/AbstractMetaTagManager.php
+++ b/Classes/Seo/MetaTag/AbstractMetaTagManager.php
@@ -23,9 +23,16 @@
  */
 abstract class AbstractMetaTagManager extends \TYPO3\CMS\Core\MetaTag\AbstractMetaTagManager
 {
+    private ?HeadlessModeInterface $headlessMode = null;
+
+    private function getHeadlessMode(): HeadlessModeInterface
+    {
+        return $this->headlessMode ??= GeneralUtility::makeInstance(HeadlessModeInterface::class);
+    }
+
     public function renderAllProperties(): string
     {
-        if (GeneralUtility::makeInstance(HeadlessModeInterface::class)->withRequest($GLOBALS['TYPO3_REQUEST'])->isEnabled()) {
+        if ($this->getHeadlessMode()->withRequest($GLOBALS['TYPO3_REQUEST'])->isEnabled()) {
             return $this->renderAllHeadlessProperties();
         }
 
@@ -34,7 +41,7 @@ public function renderAllProperties(): string
 
     public function renderProperty(string $property): string
     {
-        if (GeneralUtility::makeInstance(HeadlessModeInterface::class)->withRequest($GLOBALS['TYPO3_REQUEST'])->isEnabled()) {
+        if ($this->getHeadlessMode()->withRequest($GLOBALS['TYPO3_REQUEST'])->isEnabled()) {
             return $this->renderHeadlessProperty($property);
         }
 
diff --git a/Classes/Utility/FileUtility.php b/Classes/Utility/FileUtility.php
index e405a49b..ad69759f 100644
--- a/Classes/Utility/FileUtility.php
+++ b/Classes/Utility/FileUtility.php
@@ -215,7 +215,6 @@ public function process(FileInterface $fileReference, ProcessingConfiguration $p
 
     private function onDemandProperties(ProcessingConfiguration $processingConfiguration, array $properties): array
     {
-        $processed = [];
         $props = [];
 
         foreach ($processingConfiguration->includeProperties as $prop) {
@@ -246,7 +245,7 @@ private function onDemandProperties(ProcessingConfiguration $processingConfigura
             }
         }
 
-        return array_merge($processed, $props);
+        return $props;
     }
 
     private function filterProperties(ProcessingConfiguration $processingConfiguration, array $properties): array
@@ -329,7 +328,7 @@ public function getAbsoluteUrl(string $fileUrl): string
         $siteUrl = $this->getNormalizedParams()->getSiteUrl();
         $sitePath = str_replace($this->getNormalizedParams()->getRequestHost(), '', $siteUrl);
         $absoluteUrl = trim($fileUrl);
-        if (stripos($absoluteUrl, 'http') !== 0) {
+        if (stripos($absoluteUrl, 'http') !== 0 && !str_starts_with($absoluteUrl, '//')) {
             $fileUrl = preg_replace('#^' . preg_quote($sitePath, '#') . '#', '', $fileUrl);
             $fileUrl = $siteUrl . $fileUrl;
         }
@@ -377,9 +376,12 @@ protected function getNormalizedParams(): NormalizedParams
         return $this->contentObjectRenderer->getRequest()->getAttribute('normalizedParams');
     }
 
+    /** @var array<string, CropVariantCollection> */
+    private array $cropVariantCache = [];
+
     protected function createCropVariant(string $cropString): CropVariantCollection
     {
-        return CropVariantCollection::create($cropString);
+        return $this->cropVariantCache[$cropString] ??= CropVariantCollection::create($cropString);
     }
 
     /**
@@ -396,8 +398,8 @@ private function processAutogenerate(
         array $processedFile,
         ProcessingConfiguration $processingConfiguration
     ): array {
-        $originalWidth = $originalReference->getProperty('width');
-        $originalHeight = $originalReference->getProperty('height');
+        $originalWidth = $this->getCroppedDimensionalProperty($originalReference, 'width', $processingConfiguration->cropVariant);
+        $originalHeight = $this->getCroppedDimensionalProperty($originalReference, 'height', $processingConfiguration->cropVariant);
         $targetWidth = (int)($processingConfiguration->width !== '' ? $processingConfiguration->width : $fileReference->getProperty('width'));
         $targetHeight = (int)($processingConfiguration->height !== '' ? $processingConfiguration->height : $fileReference->getProperty('height'));
 
@@ -436,14 +438,14 @@ public function processCropVariants(
          */
         $crop = $originalFileReference->getProperty('crop');
 
-        if ($crop !== null) {
+        if ($crop !== null && $crop !== '') {
             if (!$processingConfiguration->legacyReturn) {
                 unset($processedFile['crop'], $processedFile['properties']['crop']);
             }
 
-            $cropVariants = json_decode($originalFileReference->getProperty('crop'), true);
+            $cropVariants = json_decode($crop, true);
 
-            $collection = CropVariantCollection::create($originalFileReference->getProperty('crop'));
+            $collection = $this->createCropVariant($crop);
 
             if (is_array($cropVariants) && count($cropVariants) > 1 && str_starts_with(
                 $originalFileReference->getMimeType(),
@@ -454,10 +456,10 @@ public function processCropVariants(
                         continue;
                     }
 
-                    $processingConfiguration = $processingConfiguration->withOptions(['cropVariant' => $cropVariantName]);
-                    $file = $this->process($originalFileReference, $processingConfiguration);
+                    $variantConfiguration = $processingConfiguration->withOptions(['cropVariant' => $cropVariantName]);
+                    $file = $this->process($originalFileReference, $variantConfiguration);
                     $processedFile['cropVariants'][$cropVariantName] = $this->cropVariant(
-                        $processingConfiguration,
+                        $variantConfiguration,
                         $file,
                         $cropVariants[$cropVariantName]
                     );
diff --git a/Classes/Utility/HeadlessUserInt.php b/Classes/Utility/HeadlessUserInt.php
index 4a25b1d3..40c4e0e1 100644
--- a/Classes/Utility/HeadlessUserInt.php
+++ b/Classes/Utility/HeadlessUserInt.php
@@ -71,7 +71,7 @@ public function unwrap(string $content): string
 
     protected function buildPattern(string $primary, string $nullable): string
     {
-        return self::$regexPatterns[$primary] ??= sprintf(
+        return self::$regexPatterns[$primary . '|' . $nullable] ??= sprintf(
             self::REGEX,
             preg_quote($nullable, '/'),
             preg_quote($primary, '/')
@@ -98,7 +98,8 @@ protected function replace(array $m, bool $isNullable): string
                 return $rawContent;
             }
 
-            return json_encode($rawContent);
+            $encoded = json_encode($rawContent);
+            return $encoded !== false ? $encoded : 'null';
         }
 
         $jsonEncoded = json_encode($rawContent);
diff --git a/Classes/Utility/UrlUtility.php b/Classes/Utility/UrlUtility.php
index 66fafa25..5a9af18d 100644
--- a/Classes/Utility/UrlUtility.php
+++ b/Classes/Utility/UrlUtility.php
@@ -47,6 +47,7 @@ class UrlUtility implements LoggerAwareInterface, HeadlessFrontendUrlInterface
     private array $variants = [];
     private HeadlessModeInterface $headlessMode;
     private array $frontendDomains = [];
+    private array $backendDomains = [];
 
     public function __construct(
         ?Features $features = null,
@@ -91,7 +92,10 @@ public function getFrontendUrlWithSite($url, SiteInterface $site, string $return
 
         $targetUri = new Uri($this->sanitizeBaseUrl($url));
 
-        if (!$this->headlessMode->isEnabled() || $this->alreadyFrontendLink($url) || $targetUri->getHost() === '') {
+        if (!$this->headlessMode->isEnabled() ||
+            $targetUri->getHost() === '' ||
+            $this->isExternalUrl($targetUri->getHost()) ||
+            $this->alreadyFrontendLink($targetUri->getHost())) {
             return $url;
         }
 
@@ -257,6 +261,10 @@ private function handleLanguageConfiguration(SiteLanguage $language, HeadlessFro
         $frontendFileApi = trim($langConf['frontendFileApi'] ?? '');
         $overrides = [];
 
+        if ($language->getBase()->getHost() !== '') {
+            $this->backendDomains[] = $language->getBase()->getHost();
+        }
+
         if ($frontendBase !== '') {
             $overrides['frontendBase'] =  $frontendBase;
             $this->frontendDomains[] = (new Uri($this->sanitizeBaseUrl($frontendBase)))->getHost();
@@ -283,7 +291,17 @@ private function handleSiteConfiguration(Site $site, UrlUtility $object): self
     {
         $object->conf = $site->getConfiguration();
         $object->variants = $object->conf['baseVariants'] ?? [];
+
         $this->frontendDomains = [];
+        $this->backendDomains = [];
+        $this->backendDomains[] = $site->getBase()->getHost();
+
+        foreach ($object->variants as $variant) {
+            $variantBase = trim($variant['base'] ?? '');
+            if ($variantBase !== '') {
+                $object->backendDomains[] = (new Uri($this->sanitizeBaseUrl($variantBase)))->getHost();
+            }
+        }
 
         $base = trim($object->conf['frontendBase'] ?? '');
         if ($base !== '') {
@@ -333,6 +351,9 @@ private function overrideByLanguageIfNecessary(SiteInterface $site, string $back
                 continue;
             }
 
+            if ($language->getBase()->getHost() !== '') {
+                $this->backendDomains[] = $language->getBase()->getHost();
+            }
             $this->frontendDomains[] = (new Uri($this->sanitizeBaseUrl($base)))->getHost();
 
             if ($language->getBase()->getHost() === $backendUri->getHost()) {
@@ -342,6 +363,7 @@ private function overrideByLanguageIfNecessary(SiteInterface $site, string $back
             }
         }
 
+        $this->backendDomains = array_unique($this->backendDomains);
         $this->frontendDomains = array_unique($this->frontendDomains);
 
         return $matchedLanguage;
@@ -349,8 +371,11 @@ private function overrideByLanguageIfNecessary(SiteInterface $site, string $back
 
     protected function alreadyFrontendLink(string $url): bool
     {
-        $targetUri = new Uri($this->sanitizeBaseUrl($url));
+        return in_array($url, $this->frontendDomains, true);
+    }
 
-        return in_array($targetUri->getHost(), $this->frontendDomains, true);
+    protected function isExternalUrl(string $url): bool
+    {
+        return !in_array($url, array_merge($this->backendDomains, $this->frontendDomains), true);
     }
 }
diff --git a/Tests/Unit/Middleware/CookieDomainPerSiteTest.php b/Tests/Unit/Middleware/CookieDomainPerSiteTest.php
index 9f18f489..f67b65b1 100644
--- a/Tests/Unit/Middleware/CookieDomainPerSiteTest.php
+++ b/Tests/Unit/Middleware/CookieDomainPerSiteTest.php
@@ -25,6 +25,7 @@
 use TYPO3\CMS\Core\Http\JsonResponse;
 use TYPO3\CMS\Core\Http\NormalizedParams;
 use TYPO3\CMS\Core\Http\ServerRequest;
+use TYPO3\CMS\Core\Http\Uri;
 use TYPO3\CMS\Core\Site\Entity\Site;
 use TYPO3\CMS\Core\Site\SiteFinder;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
@@ -77,6 +78,8 @@ public function emptyCookieDomain()
             ],
         ]);
 
+        $site->getBase()->willReturn(new Uri('https://www.typo3.org'));
+
         $resolver = $this->prophesize(Resolver::class);
         $resolver->evaluate(Argument::containingString('Development'))->willReturn(true);
 
@@ -135,6 +138,8 @@ public function cookieDomainIsSet()
             ],
         ]);
 
+        $site->getBase()->willReturn(new Uri('https://www.typo3.org'));
+
         $resolver = $this->prophesize(Resolver::class);
         $resolver->evaluate(Argument::containingString('Development'))->willReturn(true);
 
diff --git a/Tests/Unit/Utility/UrlUtilityTest.php b/Tests/Unit/Utility/UrlUtilityTest.php
index d570b563..9800cabd 100644
--- a/Tests/Unit/Utility/UrlUtilityTest.php
+++ b/Tests/Unit/Utility/UrlUtilityTest.php
@@ -188,6 +188,8 @@ public function testFrontendUrlsWithBaseProductionAndLocalOverride(): void
             ],
         ]);
 
+        $site->getBase()->willReturn(new Uri('https://api.typo3.org'));
+
         $siteFinder = $this->createMock(SiteFinder::class);
 
         // local override
@@ -243,6 +245,7 @@ public function testOptimizedUrlsForFrontendApp(): void
             ],
         ]);
         $site->getLanguages()->willReturn([]);
+        $site->getBase()->willReturn(new Uri('https://test-backend-api.tld'));
 
         $resolver = $this->prophesize(Resolver::class);
         $resolver->evaluate(Argument::containingString('Development'))->willReturn(true);
@@ -278,6 +281,12 @@ public function testOptimizedUrlsForFrontendApp(): void
             $urlUtility->getFrontendUrlWithSite('/test-page', $site->reveal())
         );
 
+        // do not touch external links
+        self::assertSame(
+            'https://typo3.org/headless',
+            $urlUtility->getFrontendUrlWithSite('https://typo3.org/headless', $site->reveal())
+        );
+
         // test reversed = "Testing" condition
         $resolver = $this->prophesize(Resolver::class);
         $resolver->evaluate(Argument::containingString('Development'))->willReturn(false);
@@ -346,6 +355,8 @@ public function testLanguageResolver(): void
             ],
         ]);
 
+        $site->getBase()->willReturn(new Uri('https://www.typo3.org'));
+
         $resolver = $this->prophesize(Resolver::class);
         $resolver->evaluate(Argument::containingString('Development'))->willReturn(true);
         $resolver->evaluate(Argument::containingString('Testing'))->willReturn(false);