diff --git a/app/Http/Controllers/Webhook/Github.php b/app/Http/Controllers/Webhook/Github.php
index c4fdc5fd5c..70c5eca19b 100644
--- a/app/Http/Controllers/Webhook/Github.php
+++ b/app/Http/Controllers/Webhook/Github.php
@@ -520,7 +520,7 @@ class Github extends Controller
         abort_if($this->githubAppHasManifestCredentials($github_app), 403, 'GitHub App credentials are already configured.');
 
         $api_url = data_get($github_app, 'api_url');
-        $data = Http::withBody(null)
+        $data = Http::GitSource($api_url)->withBody(null)
             ->accept('application/vnd.github+json')
             ->timeout(10)
             ->connectTimeout(5)
@@ -612,7 +612,7 @@ class Github extends Controller
 
         try {
             $jwt = generateGithubJwt($github_app);
-            $response = Http::withHeaders([
+            $response = Http::GitSource($github_app->api_url)->withHeaders([
                 'Authorization' => "Bearer $jwt",
                 'Accept' => 'application/vnd.github+json',
             ])
diff --git a/app/Http/Controllers/Webhook/Gitlab.php b/app/Http/Controllers/Webhook/Gitlab.php
index eb24b460f7..e86e51ab14 100644
--- a/app/Http/Controllers/Webhook/Gitlab.php
+++ b/app/Http/Controllers/Webhook/Gitlab.php
@@ -50,7 +50,7 @@ class Gitlab extends Controller
 
             $baseUrl = rtrim($gitlabApp->html_url, '/');
 
-            $response = Http::asForm()->post("{$baseUrl}/oauth/token", [
+            $response = Http::GitSource($baseUrl)->asForm()->post("{$baseUrl}/oauth/token", [
                 'client_id' => $gitlabApp->client_id,
                 'client_secret' => $gitlabApp->client_secret,
                 'code' => $code,
diff --git a/app/Jobs/GithubAppPermissionJob.php b/app/Jobs/GithubAppPermissionJob.php
index 7cd1b86ac0..319a202cf1 100644
--- a/app/Jobs/GithubAppPermissionJob.php
+++ b/app/Jobs/GithubAppPermissionJob.php
@@ -29,7 +29,7 @@ class GithubAppPermissionJob implements ShouldBeEncrypted, ShouldQueue
         try {
             $github_access_token = generateGithubJwt($this->github_app);
 
-            $response = Http::withHeaders([
+            $response = Http::GitSource($this->github_app->api_url)->withHeaders([
                 'Authorization' => "Bearer $github_access_token",
                 'Accept' => 'application/vnd.github+json',
             ])->get("{$this->github_app->api_url}/app");
diff --git a/app/Livewire/Source/Github/Change.php b/app/Livewire/Source/Github/Change.php
index 2dadd73661..6bb896fcc6 100644
--- a/app/Livewire/Source/Github/Change.php
+++ b/app/Livewire/Source/Github/Change.php
@@ -263,7 +263,7 @@ class Change extends Component
             }
 
             $jwt = generateGithubJwt($this->github_app);
-            $appResponse = Http::withHeaders([
+            $appResponse = Http::GitSource($this->github_app->api_url)->withHeaders([
                 'Authorization' => "Bearer $jwt",
                 'Accept' => 'application/vnd.github+json',
             ])->timeout(10)->get("{$this->github_app->api_url}/app");
diff --git a/app/Providers/AppServiceProvider.php b/app/Providers/AppServiceProvider.php
index e4d2b0a851..f09700562f 100644
--- a/app/Providers/AppServiceProvider.php
+++ b/app/Providers/AppServiceProvider.php
@@ -6,6 +6,7 @@ use App\Auth\Oidc\OidcDiscoveryService;
 use App\Auth\Oidc\OidcTokenValidator;
 use App\Auth\Oidc\Socialite\OidcProvider;
 use App\Models\PersonalAccessToken;
+use App\Rules\SafeExternalUrl;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Support\Facades\App;
 use Illuminate\Support\Facades\DB;
@@ -30,6 +31,7 @@ class AppServiceProvider extends ServiceProvider
         $this->configurePasswords();
         $this->configureSanctumModel();
         $this->configureGitHubHttp();
+        $this->configureGitLabHttp();
         $this->configureOidcSocialite();
     }
 
@@ -85,18 +87,33 @@ class AppServiceProvider extends ServiceProvider
 
     private function configureGitHubHttp(): void
     {
+        Http::macro('GitSource', function (string $url) {
+            return Http::withOptions(SafeExternalUrl::httpClientOptions($url));
+        });
+
         Http::macro('GitHub', function (string $api_url, ?string $github_access_token = null) {
             if ($github_access_token) {
-                return Http::withHeaders([
+                return Http::GitSource($api_url)->withHeaders([
                     'X-GitHub-Api-Version' => '2022-11-28',
                     'Accept' => 'application/vnd.github.v3+json',
                     'Authorization' => "Bearer $github_access_token",
                 ])->baseUrl($api_url);
             } else {
-                return Http::withHeaders([
+                return Http::GitSource($api_url)->withHeaders([
                     'Accept' => 'application/vnd.github.v3+json',
                 ])->baseUrl($api_url);
             }
         });
     }
+
+    private function configureGitLabHttp(): void
+    {
+        Http::macro('GitLab', function (string $api_url, ?string $access_token = null) {
+            $client = Http::GitSource($api_url)->withHeaders([
+                'Accept' => 'application/json',
+            ])->baseUrl($api_url);
+
+            return $access_token ? $client->withToken($access_token) : $client;
+        });
+    }
 }
diff --git a/app/Rules/SafeWebhookUrl.php b/app/Rules/SafeWebhookUrl.php
index 5a5911bee4..28e2531265 100644
--- a/app/Rules/SafeWebhookUrl.php
+++ b/app/Rules/SafeWebhookUrl.php
@@ -109,9 +109,10 @@ class SafeWebhookUrl implements ValidationRule
     /**
      * Build HTTP client options that pin the validated host to the resolved IPs.
      *
+     * @param  (Closure(string): array<int, string>)|null  $resolver
      * @return array<string, mixed>
      */
-    public static function httpClientOptions(string $url, array $trustedInternalHosts = []): array
+    public static function httpClientOptions(string $url, array $trustedInternalHosts = [], ?Closure $resolver = null): array
     {
         $options = ['allow_redirects' => false];
 
@@ -119,7 +120,7 @@ class SafeWebhookUrl implements ValidationRule
             throw new \RuntimeException('Webhook URL DNS pinning is unavailable.');
         }
 
-        $target = self::resolveUrlForRequest($url, $trustedInternalHosts);
+        $target = self::resolveUrlForRequest($url, $trustedInternalHosts, $resolver);
 
         if ($target['ips'] === [] || filter_var($target['host'], FILTER_VALIDATE_IP)) {
             return $options;
@@ -186,9 +187,13 @@ class SafeWebhookUrl implements ValidationRule
     /**
      * @return array{host: string, port: int, ips: array<int, string>}
      */
-    private static function resolveUrlForRequest(string $url, array $trustedInternalHosts = []): array
+    private static function resolveUrlForRequest(string $url, array $trustedInternalHosts = [], ?Closure $resolver = null): array
     {
-        $rule = new self(trustedInternalHosts: $trustedInternalHosts);
+        $rule = new self(resolver: $resolver, trustedInternalHosts: $trustedInternalHosts);
+        if (! filter_var($url, FILTER_VALIDATE_URL)) {
+            throw new \RuntimeException('Webhook URL is invalid.');
+        }
+
         $host = parse_url($url, PHP_URL_HOST);
         if (! is_string($host) || $host === '') {
             throw new \RuntimeException('Webhook URL host could not be resolved.');
@@ -199,6 +204,10 @@ class SafeWebhookUrl implements ValidationRule
         }
 
         $scheme = strtolower(parse_url($url, PHP_URL_SCHEME) ?? '');
+        if (! in_array($scheme, ['http', 'https'], true)) {
+            throw new \RuntimeException('Webhook URL scheme is unsafe.');
+        }
+
         $port = parse_url($url, PHP_URL_PORT) ?: ($scheme === 'https' ? 443 : 80);
         $hostForDns = rtrim($rule->normalizeHostForIpCheck(strtolower($host)), '.');
 
@@ -221,6 +230,10 @@ class SafeWebhookUrl implements ValidationRule
             }
         }
 
+        if ($rule->isBlockedHostname($hostForDns) && ! $rule->isAllowedHostname($hostForDns)) {
+            throw new \RuntimeException('Webhook URL host is unsafe.');
+        }
+
         return ['host' => $hostForDns, 'port' => $port, 'ips' => $resolvedIps];
     }
 
diff --git a/bootstrap/helpers/github.php b/bootstrap/helpers/github.php
index 66fe0c2338..b5936f2312 100644
--- a/bootstrap/helpers/github.php
+++ b/bootstrap/helpers/github.php
@@ -150,7 +150,7 @@ function encodeGithubPathSegment(string $segment): string
 
 function assertGithubClockInSync(string $apiUrl): void
 {
-    $response = Http::get("{$apiUrl}/zen");
+    $response = Http::GitSource($apiUrl)->get("{$apiUrl}/zen");
     $serverTime = CarbonImmutable::now()->setTimezone('UTC');
     $githubTime = Carbon::parse($response->header('date'));
     $timeDiff = abs($serverTime->diffInSeconds($githubTime));
@@ -186,7 +186,7 @@ function generateGithubToken(GithubApp $source, string $type)
     return match ($type) {
         'jwt' => $jwt,
         'installation' => (function () use ($source, $jwt) {
-            $response = Http::withHeaders([
+            $response = Http::GitSource($source->api_url)->withHeaders([
                 'Authorization' => "Bearer $jwt",
                 'Accept' => 'application/vnd.github.machine-man-preview+json',
             ])->post("{$source->api_url}/app/installations/{$source->installation_id}/access_tokens");
@@ -289,7 +289,7 @@ function syncGithubAppName(GithubApp $source, bool $throw = false): ?string
 
         $jwt = generateGithubAppJwt($privateKey->private_key, $source->app_id);
 
-        $response = Http::withHeaders([
+        $response = Http::GitSource($source->api_url)->withHeaders([
             'Accept' => 'application/vnd.github+json',
             'X-GitHub-Api-Version' => '2022-11-28',
             'Authorization' => "Bearer {$jwt}",
diff --git a/bootstrap/helpers/gitlab.php b/bootstrap/helpers/gitlab.php
index 743e3897b9..0ee44f2157 100644
--- a/bootstrap/helpers/gitlab.php
+++ b/bootstrap/helpers/gitlab.php
@@ -32,7 +32,7 @@ function refreshGitlabToken(GitlabApp $source): void
 
         $baseUrl = rtrim($source->html_url, '/');
 
-        $response = Http::asForm()->post("{$baseUrl}/oauth/token", [
+        $response = Http::GitSource($baseUrl)->asForm()->post("{$baseUrl}/oauth/token", [
             'client_id' => $source->client_id,
             'client_secret' => $source->client_secret,
             'refresh_token' => $source->refresh_token,
diff --git a/tests/Feature/GitSourceHttpSafetyTest.php b/tests/Feature/GitSourceHttpSafetyTest.php
new file mode 100644
index 0000000000..fd6c8af432
--- /dev/null
+++ b/tests/Feature/GitSourceHttpSafetyTest.php
@@ -0,0 +1,104 @@
+<?php
+
+use App\Models\GithubApp;
+use App\Models\GitlabApp;
+use App\Models\InstanceSettings;
+use App\Models\Team;
+use App\Models\User;
+use App\Rules\SafeExternalUrl;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\Cache;
+use Illuminate\Support\Facades\Http;
+
+uses(RefreshDatabase::class);
+
+it('rejects unsafe Git source targets when a request is built', function () {
+    expect(fn () => Http::GitHub('http://169.254.169.254', 'secret'))
+        ->toThrow(RuntimeException::class);
+});
+
+it('disables redirects and pins public GitHub requests without losing authorization', function () {
+    $request = Http::GitHub('https://api.github.com', 'secret');
+    $options = $request->getOptions();
+
+    expect($options['allow_redirects'])->toBeFalse()
+        ->and($options['curl'][CURLOPT_RESOLVE][0])->toStartWith('api.github.com:443:')
+        ->and($options['headers']['Authorization'])->toBe('Bearer secret');
+});
+
+it('uses the same guard and bearer header for GitLab requests', function () {
+    $request = Http::GitLab('https://gitlab.com/api/v4', 'gitlab-secret');
+    $options = $request->getOptions();
+
+    expect($options['allow_redirects'])->toBeFalse()
+        ->and($options['curl'][CURLOPT_RESOLVE][0])->toStartWith('gitlab.com:443:')
+        ->and($options['headers']['Authorization'])->toBe('Bearer gitlab-secret');
+});
+
+it('rejects a hostname that resolves to a private IP at request time', function () {
+    expect(fn () => SafeExternalUrl::httpClientOptions(
+        'https://api.github.com',
+        resolver: fn (string $host): array => ['169.254.169.254'],
+    ))->toThrow(RuntimeException::class, 'unsafe IP address');
+});
+
+it('requires source administration rather than ordinary team membership to configure a source', function () {
+    $team = Team::factory()->create();
+    $owner = User::factory()->create();
+    $member = User::factory()->create();
+    $team->members()->attach($owner->id, ['role' => 'owner']);
+    $team->members()->attach($member->id, ['role' => 'member']);
+
+    $this->actingAs($member);
+    session(['currentTeam' => $team]);
+    expect($member->can('create', GithubApp::class))->toBeFalse();
+
+    $this->actingAs($owner);
+    session(['currentTeam' => $team]);
+    expect($owner->can('create', GithubApp::class))->toBeTrue();
+});
+
+it('does not send a manifest conversion request to an unsafe saved source URL', function () {
+    InstanceSettings::unguarded(fn () => InstanceSettings::query()->create(['id' => 0]));
+    $team = Team::factory()->create();
+    $user = User::factory()->create();
+    $team->members()->attach($user->id, ['role' => 'owner']);
+    $app = GithubApp::create([
+        'name' => 'Unsafe source',
+        'api_url' => 'http://169.254.169.254',
+        'html_url' => 'https://github.com',
+        'team_id' => $team->id,
+    ]);
+    Cache::put('github-app-setup-state:'.hash('sha256', 'safe-test-state'), [
+        'action' => 'manifest',
+        'github_app_id' => $app->id,
+        'team_id' => $team->id,
+    ], now()->addMinutes(10));
+    Http::preventStrayRequests();
+    Http::fake(['*' => Http::response([], 200)]);
+
+    $this->actingAs($user);
+    session(['currentTeam' => $team]);
+    $this->get('/webhooks/source/github/redirect?code=test-code&state=safe-test-state');
+
+    Http::assertNothingSent();
+});
+
+it('does not send a GitLab token refresh request to an unsafe saved source URL', function () {
+    $team = Team::factory()->create();
+    $source = GitlabApp::create([
+        'name' => 'Unsafe GitLab source',
+        'api_url' => 'https://gitlab.com/api/v4',
+        'html_url' => 'http://169.254.169.254',
+        'client_id' => 'client-id',
+        'client_secret' => 'client-secret',
+        'refresh_token' => 'refresh-token',
+        'expires_at' => 0,
+        'team_id' => $team->id,
+    ]);
+    Http::preventStrayRequests();
+    Http::fake(['*' => Http::response(['access_token' => 'unsafe-token'], 200)]);
+
+    expect(fn () => refreshGitlabToken($source))->toThrow(RuntimeException::class);
+    Http::assertNothingSent();
+});
diff --git a/tests/Feature/GitlabOAuthCallbackStateTest.php b/tests/Feature/GitlabOAuthCallbackStateTest.php
index c9d693dfe2..b858ffd26f 100644
--- a/tests/Feature/GitlabOAuthCallbackStateTest.php
+++ b/tests/Feature/GitlabOAuthCallbackStateTest.php
@@ -4,6 +4,7 @@ use App\Livewire\Source\Gitlab\Change as GitlabSource;
 use App\Models\GitlabApp;
 use App\Models\Team;
 use App\Models\User;
+use App\Rules\SafeExternalUrl;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Facades\Http;
@@ -11,6 +12,11 @@ use Illuminate\Support\Facades\Http;
 uses(RefreshDatabase::class);
 
 beforeEach(function () {
+    Http::macro('GitSource', fn (string $url) => Http::withOptions(SafeExternalUrl::httpClientOptions(
+        $url,
+        resolver: fn (string $host): array => ['93.184.216.34'],
+    )));
+
     $this->team = Team::factory()->create();
     $this->user = User::factory()->create();
     $this->team->members()->attach($this->user->id, ['role' => 'owner']);
diff --git a/tests/Feature/Security/GithubAppSetupCallbackTest.php b/tests/Feature/Security/GithubAppSetupCallbackTest.php
index 9e3f8ea81a..69671f2c24 100644
--- a/tests/Feature/Security/GithubAppSetupCallbackTest.php
+++ b/tests/Feature/Security/GithubAppSetupCallbackTest.php
@@ -5,6 +5,7 @@ use App\Models\InstanceSettings;
 use App\Models\PrivateKey;
 use App\Models\Team;
 use App\Models\User;
+use App\Rules\SafeExternalUrl;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Facades\Http;
@@ -12,6 +13,11 @@ use Illuminate\Support\Facades\Http;
 uses(RefreshDatabase::class);
 
 beforeEach(function () {
+    Http::macro('GitSource', fn (string $url) => Http::withOptions(SafeExternalUrl::httpClientOptions(
+        $url,
+        resolver: fn (string $host): array => ['93.184.216.34'],
+    )));
+
     InstanceSettings::unguarded(fn () => InstanceSettings::query()->create(['id' => 0]));
 
     $this->team = Team::factory()->create();