diff --git a/.gitignore b/.gitignore
index 4061960bb..414fc83b4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,4 @@ data/infra/matomo
 docs/mercure.html
 .phpunit.result.cache
 docs/swagger/openapi-inlined.json
+config/test/dynamic_test_env.php
diff --git a/composer.json b/composer.json
index f04124d4d..3152018dd 100644
--- a/composer.json
+++ b/composer.json
@@ -74,7 +74,8 @@
         "shlinkio/php-coding-standard": "~2.5.0",
         "shlinkio/shlink-test-utils": "^4.3.1",
         "symfony/var-dumper": "^7.3",
-        "veewee/composer-run-parallel": "^1.4"
+        "veewee/composer-run-parallel": "^1.4",
+        "webimpress/safe-writer": "^2.2"
     },
     "conflict": {
         "symfony/var-exporter": ">=6.3.9,<=6.4.0"
diff --git a/config/container.php b/config/container.php
index 31e406a3d..842aa9932 100644
--- a/config/container.php
+++ b/config/container.php
@@ -16,6 +16,8 @@
 
 require 'vendor/autoload.php';
 
+// Promote env vars from dynamic test config
+loadEnvVarsFromConfig('config/test/dynamic_test_env.php', enumValues(EnvVars::class));
 // Promote env vars from installer, dev config or test config
 loadEnvVarsFromConfig(
     EnvVars::isTestEnv() ? 'config/test/shlink_test_env.php' : 'config/params/*.php',
diff --git a/config/test/constants.php b/config/test/constants.php
index f2ad124d6..dee3d5950 100644
--- a/config/test/constants.php
+++ b/config/test/constants.php
@@ -19,3 +19,5 @@
     . 'Version/18.4 Safari/605.1.15';
 const CHROMEOS_USER_AGENT = 'Mozilla/5.0 (X11; CrOS x86_64 16181.61.0) AppleWebKit/537.36 (KHTML, like Gecko) '
     . 'Chrome/134.0.6998.198 Safari/537.36';
+
+const DYNAMIC_ENV_VARS_FILE = __DIR__ . '/../../config/test/dynamic_test_env.php';
diff --git a/module/Rest/test-api/Action/MercureInfoTest.php b/module/Rest/test-api/Action/MercureInfoTest.php
new file mode 100644
index 000000000..6bb1c0bb4
--- /dev/null
+++ b/module/Rest/test-api/Action/MercureInfoTest.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkioApiTest\Shlink\Rest\Action;
+
+use PHPUnit\Framework\Attributes\Test;
+use Shlinkio\Shlink\Core\Config\EnvVars;
+use Shlinkio\Shlink\TestUtils\ApiTest\ApiTestCase;
+use ShlinkioApiTest\Shlink\Rest\Utils\WithEnvVars;
+
+class MercureInfoTest extends ApiTestCase
+{
+    #[Test]
+    public function mercureServerInfoIsReturnedIfConfigured(): void
+    {
+        $resp = $this->callApiWithKey('GET', '/mercure-info');
+        self::assertEquals(501, $resp->getStatusCode());
+    }
+
+    #[Test, WithEnvVars([
+        EnvVars::MERCURE_ENABLED->value => true,
+        EnvVars::MERCURE_PUBLIC_HUB_URL->value => 'https://mercure.example.com',
+        EnvVars::MERCURE_JWT_SECRET->value => 'mercure_jwt_key_long_enough_to_avoid_error',
+    ])]
+    public function errorIsReturnedIfMercureServerIsNotConfigured(): void
+    {
+        $resp = $this->callApiWithKey('GET', '/mercure-info');
+        $payload = $this->getJsonResponsePayload($resp);
+
+        self::assertEquals(200, $resp->getStatusCode());
+        self::assertEquals('https://mercure.example.com/.well-known/mercure', $payload['mercureHubUrl']);
+    }
+}
diff --git a/module/Rest/test-api/Middleware/CorsTest.php b/module/Rest/test-api/Middleware/CorsTest.php
index 4ed3f2cbc..e5ba8e172 100644
--- a/module/Rest/test-api/Middleware/CorsTest.php
+++ b/module/Rest/test-api/Middleware/CorsTest.php
@@ -7,7 +7,9 @@
 use GuzzleHttp\RequestOptions;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Test;
+use Shlinkio\Shlink\Core\Config\EnvVars;
 use Shlinkio\Shlink\TestUtils\ApiTest\ApiTestCase;
+use ShlinkioApiTest\Shlink\Rest\Utils\WithEnvVars;
 
 class CorsTest extends ApiTestCase
 {
@@ -61,8 +63,8 @@ public function preflightRequestsIncludeExtraCorsHeaders(string $endpoint, strin
         ]);
 
         self::assertEquals(204, $resp->getStatusCode());
-        self::assertTrue($resp->hasHeader('Access-Control-Allow-Origin'));
-        self::assertTrue($resp->hasHeader('Access-Control-Max-Age'));
+        self::assertEquals('*', $resp->getHeaderLine('Access-Control-Allow-Origin'));
+        self::assertEquals('3600', $resp->getHeaderLine('Access-Control-Max-Age'));
         self::assertEquals($expectedAllowedMethods, $resp->getHeaderLine('Access-Control-Allow-Methods'));
         self::assertEquals($allowedHeaders, $resp->getHeaderLine('Access-Control-Allow-Headers'));
     }
@@ -74,4 +76,20 @@ public static function providePreflightEndpoints(): iterable
         yield 'tags route' => ['/tags', 'GET,DELETE,PUT'];
         yield 'health route' => ['/health', 'GET'];
     }
+
+    #[Test, WithEnvVars([
+        EnvVars::CORS_MAX_AGE->value => 5000,
+        EnvVars::CORS_ALLOW_CREDENTIALS->value => true,
+        EnvVars::CORS_ALLOW_ORIGIN->value => 'example.com,localhost:8000',
+    ])]
+    public function parametersCanBeCustomized(): void
+    {
+        $resp = $this->callApiWithKey(self::METHOD_OPTIONS, '/short-urls', [
+            RequestOptions::HEADERS => ['Origin' => 'example.com'],
+        ]);
+
+        self::assertEquals('5000', $resp->getHeaderLine('Access-Control-Max-Age'));
+        self::assertEquals('example.com', $resp->getHeaderLine('Access-Control-Allow-Origin'));
+        self::assertEquals('true', $resp->getHeaderLine('Access-Control-Allow-Credentials'));
+    }
 }
diff --git a/module/Rest/test-api/Utils/ApiTestsExtension.php b/module/Rest/test-api/Utils/ApiTestsExtension.php
new file mode 100644
index 000000000..e1dbd9c0f
--- /dev/null
+++ b/module/Rest/test-api/Utils/ApiTestsExtension.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkioApiTest\Shlink\Rest\Utils;
+
+use PHPUnit\Runner\Extension\Extension;
+use PHPUnit\Runner\Extension\Facade;
+use PHPUnit\Runner\Extension\ParameterCollection;
+use PHPUnit\TextUI\Configuration\Configuration;
+use Symfony\Component\Process\Process;
+
+class ApiTestsExtension implements Extension
+{
+    public function bootstrap(Configuration $configuration, Facade $facade, ParameterCollection $parameters): void
+    {
+        $facade->registerSubscriber(new EnvSpecificTestListener());
+        $facade->registerSubscriber(new CleanDynamicEnvVarsTestListener());
+    }
+
+    public static function restartRRServer(): void
+    {
+        (new Process(['bin/rr', 'reset', '-c=config/roadrunner/.rr.test.yml']))->mustRun();
+    }
+}
diff --git a/module/Rest/test-api/Utils/CleanDynamicEnvVarsTestListener.php b/module/Rest/test-api/Utils/CleanDynamicEnvVarsTestListener.php
new file mode 100644
index 000000000..08436ca91
--- /dev/null
+++ b/module/Rest/test-api/Utils/CleanDynamicEnvVarsTestListener.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkioApiTest\Shlink\Rest\Utils;
+
+use PHPUnit\Event\Test\Finished;
+use PHPUnit\Event\Test\FinishedSubscriber;
+
+use function file_exists;
+use function unlink;
+
+use const ShlinkioTest\Shlink\DYNAMIC_ENV_VARS_FILE;
+
+/**
+ * Tries to delete the dynamic env vars after a test has finished, if any, so that it does not affect subsequent tests
+ */
+class CleanDynamicEnvVarsTestListener implements FinishedSubscriber
+{
+    public function notify(Finished $event): void
+    {
+        if (file_exists(DYNAMIC_ENV_VARS_FILE)) {
+            unlink(DYNAMIC_ENV_VARS_FILE);
+            // Restart server again so that it removes the env vars from the file that has just been deleted
+            ApiTestsExtension::restartRRServer();
+        }
+    }
+}
diff --git a/module/Rest/test-api/Utils/EnvSpecificTestListener.php b/module/Rest/test-api/Utils/EnvSpecificTestListener.php
new file mode 100644
index 000000000..64b2037c4
--- /dev/null
+++ b/module/Rest/test-api/Utils/EnvSpecificTestListener.php
@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkioApiTest\Shlink\Rest\Utils;
+
+use PHPUnit\Event\Code\TestMethod;
+use PHPUnit\Event\Test\PreparationStarted;
+use PHPUnit\Event\Test\PreparationStartedSubscriber;
+use ReflectionMethod;
+use Webimpress\SafeWriter\FileWriter;
+
+use function sprintf;
+use function var_export;
+
+use const ShlinkioTest\Shlink\DYNAMIC_ENV_VARS_FILE;
+
+/**
+ * Checks if a test to be executed has the WithEnvVars attribute, and if so, creates a file with the env vars it defines
+ * and restarts RoadRunner test server so that those env vars are applied.
+ */
+class EnvSpecificTestListener implements PreparationStartedSubscriber
+{
+    public function notify(PreparationStarted $event): void
+    {
+        $test = $event->test();
+        if (! ($test instanceof TestMethod)) {
+            return;
+        }
+
+        $className = $test->className();
+        $methodName = $test->methodName();
+
+        $reflection = new ReflectionMethod($className, $methodName);
+        $attributes = $reflection->getAttributes(WithEnvVars::class);
+
+        // If the method has the attribute, generate a temporary env file, and restart the RoadRunner server
+        if (! empty($attributes)) {
+            /** @var WithEnvVars $withEnvVars */
+            $withEnvVars = $attributes[0]->newInstance();
+            $this->createDynamicEnvVarsFile($withEnvVars->envVars);
+            ApiTestsExtension::restartRRServer();
+        }
+    }
+
+    private function createDynamicEnvVarsFile(array $envVars): void
+    {
+        $template = <<<TEMPLATE
+            <?php
+            
+            /* Shlink config generated by %s */
+            
+            return %s;
+            
+            TEMPLATE;
+        $content = sprintf($template, self::class, var_export($envVars, return: true));
+
+        FileWriter::writeFile(DYNAMIC_ENV_VARS_FILE, $content);
+    }
+}
diff --git a/module/Rest/test-api/Utils/WithEnvVars.php b/module/Rest/test-api/Utils/WithEnvVars.php
new file mode 100644
index 000000000..e103c9e10
--- /dev/null
+++ b/module/Rest/test-api/Utils/WithEnvVars.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkioApiTest\Shlink\Rest\Utils;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_METHOD)]
+final readonly class WithEnvVars
+{
+    public function __construct(public array $envVars)
+    {
+    }
+}
diff --git a/phpunit-api.xml b/phpunit-api.xml
index dc6823223..80bdd178f 100644
--- a/phpunit-api.xml
+++ b/phpunit-api.xml
@@ -20,4 +20,8 @@
             <directory>./module/Rest/src</directory>
         </include>
     </source>
+
+    <extensions>
+        <bootstrap class="ShlinkioApiTest\Shlink\Rest\Utils\ApiTestsExtension" />
+    </extensions>
 </phpunit>