diff --git a/app/Http/Kernel.php b/app/Http/Kernel.php
index e9d7b82b2..515d40c62 100644
--- a/app/Http/Kernel.php
+++ b/app/Http/Kernel.php
@@ -14,7 +14,7 @@ class Kernel extends HttpKernel
      * @var array<int, class-string|string>
      */
     protected $middleware = [
-        // \App\Http\Middleware\TrustHosts::class,
+        \App\Http\Middleware\TrustHosts::class,
         \App\Http\Middleware\TrustProxies::class,
         \Illuminate\Http\Middleware\HandleCors::class,
         \App\Http\Middleware\PreventRequestsDuringMaintenance::class,
diff --git a/app/Http/Middleware/TrustHosts.php b/app/Http/Middleware/TrustHosts.php
index c9c58bddc..c2a2cb41a 100644
--- a/app/Http/Middleware/TrustHosts.php
+++ b/app/Http/Middleware/TrustHosts.php
@@ -2,7 +2,10 @@
 
 namespace App\Http\Middleware;
 
+use App\Models\InstanceSettings;
 use Illuminate\Http\Middleware\TrustHosts as Middleware;
+use Illuminate\Support\Facades\Cache;
+use Spatie\Url\Url;
 
 class TrustHosts extends Middleware
 {
@@ -13,8 +16,37 @@ class TrustHosts extends Middleware
      */
     public function hosts(): array
     {
-        return [
-            $this->allSubdomainsOfApplicationUrl(),
-        ];
+        $trustedHosts = [];
+
+        // Trust the configured FQDN from InstanceSettings (cached to avoid DB query on every request)
+        // Use empty string as sentinel value instead of null so negative results are cached
+        $fqdnHost = Cache::remember('instance_settings_fqdn_host', 300, function () {
+            try {
+                $settings = InstanceSettings::get();
+                if ($settings && $settings->fqdn) {
+                    $url = Url::fromString($settings->fqdn);
+                    $host = $url->getHost();
+
+                    return $host ?: '';
+                }
+            } catch (\Exception $e) {
+                // If instance settings table doesn't exist yet (during installation),
+                // return empty string (sentinel) so this result is cached
+            }
+
+            return '';
+        });
+
+        // Convert sentinel value back to null for consumption
+        $fqdnHost = $fqdnHost !== '' ? $fqdnHost : null;
+
+        if ($fqdnHost) {
+            $trustedHosts[] = $fqdnHost;
+        }
+
+        // Trust all subdomains of APP_URL as fallback
+        $trustedHosts[] = $this->allSubdomainsOfApplicationUrl();
+
+        return array_filter($trustedHosts);
     }
 }
diff --git a/app/Models/InstanceSettings.php b/app/Models/InstanceSettings.php
index ac95bb8a9..cd1c05de4 100644
--- a/app/Models/InstanceSettings.php
+++ b/app/Models/InstanceSettings.php
@@ -35,13 +35,18 @@ class InstanceSettings extends Model
     protected static function booted(): void
     {
         static::updated(function ($settings) {
-            if ($settings->isDirty('helper_version')) {
+            if ($settings->wasChanged('helper_version')) {
                 Server::chunkById(100, function ($servers) {
                     foreach ($servers as $server) {
                         PullHelperImageJob::dispatch($server);
                     }
                 });
             }
+
+            // Clear trusted hosts cache when FQDN changes
+            if ($settings->wasChanged('fqdn')) {
+                \Cache::forget('instance_settings_fqdn_host');
+            }
         });
     }
 
diff --git a/tests/Feature/TrustHostsMiddlewareTest.php b/tests/Feature/TrustHostsMiddlewareTest.php
new file mode 100644
index 000000000..f875a235e
--- /dev/null
+++ b/tests/Feature/TrustHostsMiddlewareTest.php
@@ -0,0 +1,229 @@
+<?php
+
+use App\Http\Middleware\TrustHosts;
+use App\Models\InstanceSettings;
+use Illuminate\Support\Facades\Cache;
+
+uses(\Illuminate\Foundation\Testing\RefreshDatabase::class);
+
+beforeEach(function () {
+    // Clear cache before each test to ensure isolation
+    Cache::forget('instance_settings_fqdn_host');
+});
+
+it('trusts the configured FQDN from InstanceSettings', function () {
+    // Create instance settings with FQDN
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://coolify.example.com']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('coolify.example.com');
+});
+
+it('rejects password reset request with malicious host header', function () {
+    // Set up instance settings with legitimate FQDN
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://coolify.example.com']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // The malicious host should NOT be in the trusted hosts
+    expect($hosts)->not->toContain('coolify.example.com.evil.com');
+    expect($hosts)->toContain('coolify.example.com');
+});
+
+it('handles missing FQDN gracefully', function () {
+    // Create instance settings without FQDN
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => null]
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // Should still return APP_URL pattern without throwing
+    expect($hosts)->not->toBeEmpty();
+});
+
+it('filters out null and empty values from trusted hosts', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => '']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // Should not contain empty strings or null
+    foreach ($hosts as $host) {
+        if ($host !== null) {
+            expect($host)->not->toBeEmpty();
+        }
+    }
+});
+
+it('extracts host from FQDN with protocol and port', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://coolify.example.com:8443']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('coolify.example.com');
+});
+
+it('handles exception during InstanceSettings fetch', function () {
+    // Drop the instance_settings table to simulate installation
+    \Schema::dropIfExists('instance_settings');
+
+    $middleware = new TrustHosts($this->app);
+
+    // Should not throw an exception
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->not->toBeEmpty();
+});
+
+it('trusts IP addresses with port', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://65.21.3.91:8000']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('65.21.3.91');
+});
+
+it('trusts IP addresses without port', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://192.168.1.100']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('192.168.1.100');
+});
+
+it('rejects malicious host when using IP address', function () {
+    // Simulate an instance using IP address
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://65.21.3.91:8000']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // The malicious host attempting to mimic the IP should NOT be trusted
+    expect($hosts)->not->toContain('65.21.3.91.evil.com');
+    expect($hosts)->not->toContain('evil.com');
+    expect($hosts)->toContain('65.21.3.91');
+});
+
+it('trusts IPv6 addresses', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://[2001:db8::1]:8000']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // IPv6 addresses are enclosed in brackets, getHost() should handle this
+    expect($hosts)->toContain('[2001:db8::1]');
+});
+
+it('invalidates cache when FQDN is updated', function () {
+    // Set initial FQDN
+    $settings = InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://old-domain.com']
+    );
+
+    // First call should cache it
+    $middleware = new TrustHosts($this->app);
+    $hosts1 = $middleware->hosts();
+    expect($hosts1)->toContain('old-domain.com');
+
+    // Verify cache exists
+    expect(Cache::has('instance_settings_fqdn_host'))->toBeTrue();
+
+    // Update FQDN - should trigger cache invalidation
+    $settings->fqdn = 'https://new-domain.com';
+    $settings->save();
+
+    // Cache should be cleared
+    expect(Cache::has('instance_settings_fqdn_host'))->toBeFalse();
+
+    // New call should return updated host
+    $middleware2 = new TrustHosts($this->app);
+    $hosts2 = $middleware2->hosts();
+    expect($hosts2)->toContain('new-domain.com');
+    expect($hosts2)->not->toContain('old-domain.com');
+});
+
+it('caches trusted hosts to avoid database queries on every request', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://coolify.example.com']
+    );
+
+    // Clear cache first
+    Cache::forget('instance_settings_fqdn_host');
+
+    // First call - should query database and cache result
+    $middleware1 = new TrustHosts($this->app);
+    $hosts1 = $middleware1->hosts();
+
+    // Verify result is cached
+    expect(Cache::has('instance_settings_fqdn_host'))->toBeTrue();
+    expect(Cache::get('instance_settings_fqdn_host'))->toBe('coolify.example.com');
+
+    // Subsequent calls should use cache (no DB query)
+    $middleware2 = new TrustHosts($this->app);
+    $hosts2 = $middleware2->hosts();
+
+    expect($hosts1)->toBe($hosts2);
+    expect($hosts2)->toContain('coolify.example.com');
+});
+
+it('caches negative results when no FQDN is configured', function () {
+    // Create instance settings without FQDN
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => null]
+    );
+
+    // Clear cache first
+    Cache::forget('instance_settings_fqdn_host');
+
+    // First call - should query database and cache empty string sentinel
+    $middleware1 = new TrustHosts($this->app);
+    $hosts1 = $middleware1->hosts();
+
+    // Verify empty string sentinel is cached (not null, which wouldn't be cached)
+    expect(Cache::has('instance_settings_fqdn_host'))->toBeTrue();
+    expect(Cache::get('instance_settings_fqdn_host'))->toBe('');
+
+    // Subsequent calls should use cached sentinel value
+    $middleware2 = new TrustHosts($this->app);
+    $hosts2 = $middleware2->hosts();
+
+    expect($hosts1)->toBe($hosts2);
+    // Should only contain APP_URL pattern, not any FQDN
+    expect($hosts2)->not->toBeEmpty();
+});