diff --git a/app/code/Magento/Store/Model/Config/Placeholder.php b/app/code/Magento/Store/Model/Config/Placeholder.php
index 37c61ab418a6e..5f489fc070eb8 100644
--- a/app/code/Magento/Store/Model/Config/Placeholder.php
+++ b/app/code/Magento/Store/Model/Config/Placeholder.php
@@ -6,13 +6,16 @@
 
 namespace Magento\Store\Model\Config;
 
+use Magento\Framework\App\RequestInterface;
+use Magento\Framework\Exception\LocalizedException;
+
 /**
  * Placeholder configuration values processor. Replace placeholders in configuration with config values
  */
 class Placeholder implements PlaceholderInterface
 {
     /**
-     * @var \Magento\Framework\App\RequestInterface
+     * @var RequestInterface
      */
     protected $request;
 
@@ -27,11 +30,11 @@ class Placeholder implements PlaceholderInterface
     protected $urlPlaceholder;
 
     /**
-     * @param \Magento\Framework\App\RequestInterface $request
+     * @param RequestInterface $request
      * @param string[] $urlPaths
      * @param string $urlPlaceholder
      */
-    public function __construct(\Magento\Framework\App\RequestInterface $request, $urlPaths, $urlPlaceholder)
+    public function __construct(RequestInterface $request, $urlPaths, $urlPlaceholder)
     {
         $this->request        = $request;
         $this->urlPaths       = $urlPaths;
@@ -43,6 +46,7 @@ public function __construct(\Magento\Framework\App\RequestInterface $request, $u
      *
      * @param array $data
      * @return array
+     * @throws LocalizedException
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
     public function process(array $data = [])
@@ -71,6 +75,7 @@ function (&$value, $key, $data) {
      * @param array &$data
      * @param string $path
      * @return void
+     * @throws LocalizedException
      */
     protected function _processData(&$data, $path)
     {
@@ -90,30 +95,42 @@ protected function _processData(&$data, $path)
      * @param string $value
      * @param array $data
      * @return string
+     * @throws LocalizedException
      */
     protected function _processPlaceholders($value, $data)
     {
         $placeholder = $this->_getPlaceholder($value);
-        if ($placeholder) {
-            $url = false;
-            if ($placeholder == 'unsecure_base_url') {
-                $url = $this->_getValue($this->urlPaths['unsecureBaseUrl'], $data);
-            } elseif ($placeholder == 'secure_base_url') {
-                $url = $this->_getValue($this->urlPaths['secureBaseUrl'], $data);
-            }
+        if (!$placeholder) {
+            return $value;
+        }
 
-            if ($url) {
-                $value = str_replace('{{' . $placeholder . '}}', $url, $value);
-            } elseif (strpos($value, (string)$this->urlPlaceholder) !== false) {
-                $distroBaseUrl = $this->request->getDistroBaseUrl();
+        $url = null;
+        if ($placeholder === 'unsecure_base_url') {
+            $url = $this->_getValue($this->urlPaths['unsecureBaseUrl'], $data);
+        } elseif ($placeholder === 'secure_base_url') {
+            $url = $this->_getValue($this->urlPaths['secureBaseUrl'], $data);
+        }
 
-                $value = str_replace($this->urlPlaceholder, $distroBaseUrl, $value);
-            }
+        $originalValue = $value;
 
-            if (null !== $this->_getPlaceholder($value)) {
-                $value = $this->_processPlaceholders($value, $data);
-            }
+        if ($url) {
+            $value = str_replace('{{' . $placeholder . '}}', $url, $value);
+        } elseif (str_contains((string) $value, (string) $this->urlPlaceholder)) {
+            $value = str_replace($this->urlPlaceholder, $this->request->getDistroBaseUrl(), $value);
+        } else {
+            $configPath = $placeholder === 'secure_base_url'
+                ? $this->urlPaths['secureBaseUrl']
+                : $this->urlPaths['unsecureBaseUrl'];
+            throw new LocalizedException(
+                __('Cannot resolve "{{%1}}" because "%2" is empty.', $placeholder, $configPath)
+            );
+        }
+
+        // Only recurse when the value changed; otherwise unresolved placeholders loop forever.
+        if ($value !== $originalValue && $this->_getPlaceholder($value) !== null) {
+            $value = $this->_processPlaceholders($value, $data);
         }
+
         return $value;
     }
 
@@ -125,11 +142,14 @@ protected function _processPlaceholders($value, $data)
      */
     protected function _getPlaceholder($value)
     {
-        if (is_string($value) && preg_match('/{{(.*)}}.*/', $value, $matches)) {
+        if (!is_string($value) || $value === '') {
+            return null;
+        }
+        if (preg_match('/{{(.*)}}.*/', $value, $matches)) {
             $placeholder = $matches[1];
-            if ($placeholder == 'unsecure_base_url' ||
-                $placeholder == 'secure_base_url' ||
-                strpos($value, (string)$this->urlPlaceholder) !== false
+            if ($placeholder === 'unsecure_base_url' ||
+                $placeholder === 'secure_base_url' ||
+                str_contains($value, (string) $this->urlPlaceholder)
             ) {
                 return $placeholder;
             }
@@ -142,7 +162,7 @@ protected function _getPlaceholder($value)
      *
      * @param string $path
      * @param array $data
-     * @return array|null
+     * @return array|string|null
      */
     protected function _getValue($path, array $data)
     {
diff --git a/app/code/Magento/Store/Test/Unit/Model/Config/PlaceholderTest.php b/app/code/Magento/Store/Test/Unit/Model/Config/PlaceholderTest.php
index a157d89a77758..a62840e7c0547 100644
--- a/app/code/Magento/Store/Test/Unit/Model/Config/PlaceholderTest.php
+++ b/app/code/Magento/Store/Test/Unit/Model/Config/PlaceholderTest.php
@@ -8,15 +8,17 @@
 namespace Magento\Store\Test\Unit\Model\Config;
 
 use Magento\Framework\App\Request\Http;
-use Magento\Store\Model\Config\Processor\Placeholder as PlaceholderProcessor;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Store\Model\Config\Placeholder;
 use Magento\Store\Model\Store;
+use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class PlaceholderTest extends TestCase
 {
     /**
-     * @var PlaceholderProcessor
+     * @var Placeholder
      */
     protected $_model;
 
@@ -35,7 +37,7 @@ protected function setUp(): void
         )->willReturn(
             'http://localhost/'
         );
-        $this->_model = new \Magento\Store\Model\Config\Placeholder(
+        $this->_model = new Placeholder(
             $this->_requestMock,
             [
                 'unsecureBaseUrl' => Store::XML_PATH_UNSECURE_BASE_URL,
@@ -83,4 +85,93 @@ public function testProcessEmptyArray()
         $expectedResult = [];
         $this->assertEquals($expectedResult, $this->_model->process($data));
     }
+
+    /**
+     * @param mixed $secureBaseUrl
+     */
+    #[DataProvider('emptySecureBaseUrlDataProvider')]
+    public function testProcessThrowsWhenSecureBaseUrlIsEmpty($secureBaseUrl): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{secure_base_url}}" because "web/secure/base_url" is empty.'
+        );
+
+        $this->_model->process([
+            'web' => [
+                'unsecure' => [
+                    'base_url' => 'http://localhost/',
+                ],
+                'secure' => [
+                    'base_url' => $secureBaseUrl,
+                    'base_link_url' => '{{secure_base_url}}website/de',
+                ],
+            ],
+        ]);
+    }
+
+    /**
+     * @return array
+     */
+    public static function emptySecureBaseUrlDataProvider(): array
+    {
+        return [
+            'null' => [null],
+            'empty string' => [''],
+        ];
+    }
+
+    /**
+     * @param mixed $unsecureBaseUrl
+     */
+    #[DataProvider('emptyUnsecureBaseUrlDataProvider')]
+    public function testProcessThrowsWhenUnsecureBaseUrlIsEmpty($unsecureBaseUrl): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{unsecure_base_url}}" because "web/unsecure/base_url" is empty.'
+        );
+
+        $this->_model->process([
+            'web' => [
+                'unsecure' => [
+                    'base_url' => $unsecureBaseUrl,
+                    'base_link_url' => '{{unsecure_base_url}}website/de',
+                ],
+                'secure' => [
+                    'base_url' => 'https://localhost/',
+                ],
+            ],
+        ]);
+    }
+
+    /**
+     * @return array
+     */
+    public static function emptyUnsecureBaseUrlDataProvider(): array
+    {
+        return [
+            'null' => [null],
+            'empty string' => [''],
+        ];
+    }
+
+    public function testProcessThrowsWhenSecureBaseUrlPathIsMissing(): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{secure_base_url}}" because "web/secure/base_url" is empty.'
+        );
+
+        $this->_model->process([
+            'web' => [
+                'unsecure' => [
+                    'base_url' => 'http://localhost/',
+                ],
+                'secure' => [
+                    'base_link_url' => '{{secure_base_url}}website/de',
+                ],
+            ],
+        ]);
+    }
 }
diff --git a/dev/tests/integration/testsuite/Magento/Store/Model/Config/PlaceholderTest.php b/dev/tests/integration/testsuite/Magento/Store/Model/Config/PlaceholderTest.php
new file mode 100644
index 0000000000000..b67a0638a174a
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/Store/Model/Config/PlaceholderTest.php
@@ -0,0 +1,197 @@
+<?php
+/**
+ * Copyright 2026 Adobe
+ * All Rights Reserved.
+ */
+declare(strict_types=1);
+
+namespace Magento\Store\Model\Config;
+
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Store\Model\Store;
+use Magento\TestFramework\Helper\Bootstrap;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Integration coverage for config placeholder processing when base URL is empty.
+ *
+ * @magentoAppIsolation enabled
+ */
+class PlaceholderTest extends TestCase
+{
+    /**
+     * @var Placeholder
+     */
+    private $placeholder;
+
+    /**
+     * @inheritDoc
+     */
+    protected function setUp(): void
+    {
+        $this->placeholder = Bootstrap::getObjectManager()->create(
+            Placeholder::class,
+            [
+                'urlPaths' => [
+                    'unsecureBaseUrl' => Store::XML_PATH_UNSECURE_BASE_URL,
+                    'secureBaseUrl' => Store::XML_PATH_SECURE_BASE_URL,
+                ],
+                'urlPlaceholder' => Store::BASE_URL_PLACEHOLDER,
+            ]
+        );
+    }
+
+    /**
+     * Happy path: placeholders resolve using configured base URLs.
+     *
+     * @return void
+     */
+    public function testProcessResolvesBaseUrlPlaceholders(): void
+    {
+        $data = [
+            'web' => [
+                'unsecure' => [
+                    'base_url' => 'http://example.test/',
+                    'base_link_url' => '{{unsecure_base_url}}path/',
+                ],
+                'secure' => [
+                    'base_url' => 'https://example.test/',
+                    'base_link_url' => '{{secure_base_url}}path/',
+                ],
+            ],
+        ];
+
+        $result = $this->placeholder->process($data);
+
+        $this->assertSame('http://example.test/path/', $result['web']['unsecure']['base_link_url']);
+        $this->assertSame('https://example.test/path/', $result['web']['secure']['base_link_url']);
+    }
+
+    /**
+     * NULL secure base URL must not recurse infinitely; a clear exception is required.
+     *
+     * @return void
+     */
+    public function testProcessThrowsWhenSecureBaseUrlIsNull(): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{secure_base_url}}" because "web/secure/base_url" is empty.'
+        );
+
+        $this->placeholder->process([
+            'web' => [
+                'unsecure' => [
+                    'base_url' => 'http://example.test/',
+                ],
+                'secure' => [
+                    'base_url' => null,
+                    'base_link_url' => '{{secure_base_url}}',
+                ],
+            ],
+        ]);
+    }
+
+    /**
+     * Empty-string secure base URL must fail the same way as NULL.
+     *
+     * @return void
+     */
+    public function testProcessThrowsWhenSecureBaseUrlIsEmptyString(): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{secure_base_url}}" because "web/secure/base_url" is empty.'
+        );
+
+        $this->placeholder->process([
+            'web' => [
+                'unsecure' => [
+                    'base_url' => 'http://example.test/',
+                ],
+                'secure' => [
+                    'base_url' => '',
+                    'base_link_url' => '{{secure_base_url}}checkout/',
+                ],
+            ],
+        ]);
+    }
+
+    /**
+     * Missing secure base URL path must not recurse when a dependent placeholder is processed.
+     *
+     * @return void
+     */
+    public function testProcessThrowsWhenSecureBaseUrlIsMissing(): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{secure_base_url}}" because "web/secure/base_url" is empty.'
+        );
+
+        $this->placeholder->process([
+            'web' => [
+                'unsecure' => [
+                    'base_url' => 'http://example.test/',
+                ],
+                'secure' => [
+                    'base_link_url' => '{{secure_base_url}}',
+                ],
+            ],
+        ]);
+    }
+
+    /**
+     * NULL unsecure base URL must produce a localizable, path-specific error.
+     *
+     * @return void
+     */
+    public function testProcessThrowsWhenUnsecureBaseUrlIsNull(): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{unsecure_base_url}}" because "web/unsecure/base_url" is empty.'
+        );
+
+        $this->placeholder->process([
+            'web' => [
+                'unsecure' => [
+                    'base_url' => null,
+                    'base_link_url' => '{{unsecure_base_url}}',
+                ],
+                'secure' => [
+                    'base_url' => 'https://example.test/',
+                ],
+            ],
+        ]);
+    }
+
+    /**
+     * Scope-level processor used by config post-processing must surface the same failure.
+     *
+     * @return void
+     */
+    public function testProcessorThrowsWhenSecureBaseUrlIsNull(): void
+    {
+        $this->expectException(LocalizedException::class);
+        $this->expectExceptionMessage(
+            'Cannot resolve "{{secure_base_url}}" because "web/secure/base_url" is empty.'
+        );
+
+        /** @var Processor\Placeholder $processor */
+        $processor = Bootstrap::getObjectManager()->get(Processor\Placeholder::class);
+        $processor->process([
+            'default' => [
+                'web' => [
+                    'unsecure' => [
+                        'base_url' => 'http://example.test/',
+                    ],
+                    'secure' => [
+                        'base_url' => null,
+                        'base_link_url' => '{{secure_base_url}}',
+                    ],
+                ],
+            ],
+        ]);
+    }
+}