Laravel Security Best Practices

Constraints

• Apply @rules/security/backend.md and @rules/security/frontend.md
• Apply @rules/php/core-standards.mdc — final classes, declare(strict_types=1), typed signatures
• If the project uses Laravel, also apply @rules/laravel/laravel.mdc, @rules/laravel/architecture.mdc, @rules/laravel/filament.mdc, @rules/laravel/livewire.mdc
• Stack: Laravel 11 / PHP 8.3, Filament, Livewire, Alpine.js, Blade, Tailwind, Pest, Vite, MySQL, Redis
• Never hardcode secrets; never reveal them in output
• Hard limits: this file stays <= 500 lines and <= 5000 tokens

Purpose

Secure-by-default building blocks for security-sensitive Laravel work. Use the matching section, copy the minimal snippet, and verify against the checklist. For an audit of existing code use @skills/security-review/SKILL.md.

Use when

• Setting up authentication / authorization (Sanctum, gates, policies, middleware)
• Configuring production settings and environment variables
• Writing secure Eloquent queries and models
• Hardening CSRF / XSS / input validation / file uploads / API endpoints
• Managing secrets, queue payloads, and security event logging

Production Configuration

// config/app.php
'debug' => (bool) env('APP_DEBUG', false), // CRITICAL: never true in production
'key' => env('APP_KEY'),                    // php artisan key:generate

// config/session.php
'secure' => env('SESSION_SECURE_COOKIE', true),
'http_only' => true,
'same_site' => 'lax',

Validate required config at boot and fail fast:

// AppServiceProvider::boot()
foreach (['app.key', 'database.connections.mysql.database'] as $key) {
    if (empty(config($key))) {
        throw new RuntimeException("Missing required config key: {$key}");
    }
}

HTTPS and trusted proxies:

if (app()->environment('production')) {
    URL::forceScheme('https');
}
// Use specific CIDR ranges, never '*' (X-Forwarded-* spoofing)
'trusted_proxies' => ['10.0.0.0/8', '172.16.0.0/12'],

Keep .env out of version control (.gitignore ships with .env); ship .env.example with empty placeholders.

Authentication

Sanctum (API tokens)

// config/sanctum.php
'expiration' => 60 * 24,                          // minutes; null = never
'token_prefix' => env('SANCTUM_TOKEN_PREFIX', ''),

$token = $user->createToken('api', ['posts:read', 'posts:write'])->plainTextToken;

Route::middleware('auth:sanctum')->group(function () {
    Route::get('/posts', [PostController::class, 'index'])->middleware('abilities:posts:read');
    Route::post('/posts', [PostController::class, 'store'])->middleware('abilities:posts:write');
});

Passwords

// config/hashing.php — bcrypt rounds >= 12, or Argon2id
'bcrypt' => ['rounds' => env('BCRYPT_ROUNDS', 12)],

// FormRequest rules
'password' => [
    'required', 'confirmed',
    Password::min(12)->letters()->mixedCase()->numbers()->symbols()->uncompromised(),
],

Sessions

// config/session.php — 'driver' => 'database' or 'redis' (avoid 'file' in prod)

public function store(LoginRequest $request): RedirectResponse
{
    $request->authenticate();
    $request->session()->regenerate(); // CRITICAL: prevents session fixation
    return redirect()->intended('/dashboard');
}

public function destroy(Request $request): RedirectResponse
{
    Auth::guard('web')->logout();
    $request->session()->invalidate();
    $request->session()->regenerateToken();
    return redirect('/');
}

Authorization

Gates

// AppServiceProvider::boot()
Gate::define('update-post', fn (User $user, Post $post): bool => $user->id === $post->user_id);

Gate::before(function (User $user, string $ability): ?bool {
    return $user->role === 'super-admin' ? true : null; // null = fall through
});

// Controller
Gate::authorize('update-post', $post);

Policies

final class PostPolicy
{
    public function view(?User $user, Post $post): bool
    {
        return $post->is_published || ($user && $user->id === $post->user_id);
    }

    public function update(User $user, Post $post): bool
    {
        return $user->id === $post->user_id;
    }
}

// Controller: $this->authorize('update', $post);
// Blade: @can('update', $post) ... @endcan

Laravel 11 auto-discovers policies by naming convention; register explicitly only when names differ.

Middleware

Route::put('/posts/{post}', [PostController::class, 'update'])->middleware('can:update,post');

Route::middleware(['auth', 'role:admin'])->group(function () {
    Route::get('/admin', [AdminController::class, 'index']);
});

For Filament, enforce access via policies and canAccessPanel(); for Livewire, re-check authorization inside actions — a mounted component is not an authorization boundary (@rules/laravel/filament.mdc, @rules/laravel/livewire.mdc).

Eloquent Security

Mass assignment

final class User extends Authenticatable
{
    protected $fillable = ['name', 'email', 'phone', 'avatar'];
    // NEVER list 'role', 'is_admin'; NEVER use $guarded = []
}

User::create($request->validated());        // GOOD: validated fields only
// User::create($request->all());           // VULNERABLE

SQL injection

User::where('email', $userInput)->first();                  // parameterized
User::whereRaw('email = ?', [$userInput])->first();         // parameterized
DB::select('SELECT * FROM users WHERE email = ?', [$input]); // parameterized

// VULNERABLE — never interpolate user input:
// User::whereRaw("email = '{$userInput}'")->first();
// User::orderByRaw($userInput);  DB::statement("... '{$userInput}'");

Casting and hidden attributes

final class User extends Authenticatable
{
    protected $casts = [
        'is_admin' => 'boolean',
        'settings' => 'array',
        'metadata' => 'encrypted:array', // Laravel 11 encrypted cast
        'password' => 'hashed',          // auto-hash on set
    ];

    protected $hidden = ['password', 'remember_token', 'two_factor_secret'];
}

CSRF Protection

CSRF is on by default for the web group. State-changing forms need @csrf:

<form method="POST" action="/posts">@csrf ...</form>

Exclude only specific signature-verified webhooks — never blanket api/* (stateful Sanctum needs CSRF):

// bootstrap/app.php — $middleware->validateCsrfTokens(except: ['stripe/*'])

For JS, send the token header (Axios ships preconfigured in Laravel):

<meta name="csrf-token" content="{{ csrf_token() }}">

XSS Prevention

{{ $userInput }}        {{-- SAFE: auto-escaped --}}
{!! $userInput !!}      {{-- DANGEROUS: raw, never with user input --}}
{!! $trustedHtml !!}    {{-- only for content you fully control --}}

<script>
    const user = @js($user);      {{-- escaped for JS context --}}
    const cfg  = @json($config);
</script>

When user HTML must survive, purify with an allowlist before storing/output:

// composer require ezyang/htmlpurifier
$config = \HTMLPurifier_Config::createDefault();
$config->set('HTML.Allowed', 'p,b,i,a[href],ul,ol,li,br');
$config->set('URI.AllowedSchemes', ['http', 'https', 'mailto']);
$clean = (new \HTMLPurifier($config))->purify($dirty);

In Alpine, prefer x-text over x-html; only use x-html on sanitized content. Add security headers via middleware:

$response->headers->set('X-Content-Type-Options', 'nosniff');
$response->headers->set('X-Frame-Options', 'DENY');
$response->headers->set('Referrer-Policy', 'strict-origin-when-cross-origin');
$response->headers->set('Content-Security-Policy',
    "default-src 'self'; frame-ancestors 'none'");

Input Validation

Always validate through a FormRequest; never persist $request->all():

final class StorePostRequest extends FormRequest
{
    public function authorize(): bool
    {
        return $this->user()?->can('create', Post::class) ?? false;
    }

    public function rules(): array
    {
        return [
            'title'   => ['required', 'string', 'max:255'],
            'content' => ['required', 'string', 'max:10000'],
            'tags'    => ['array'],
            'tags.*'  => ['integer', 'exists:tags,id'],
        ];
    }
}

Keep validation messages generic — never leak which auth factor failed, whether a record exists, or framework internals (@rules/security/backend.md).

API Security

Rate limiting

// AppServiceProvider::boot()
RateLimiter::for('api', fn (Request $r) =>
    Limit::perMinute(60)->by($r->user()?->id ?: $r->ip()));

RateLimiter::for('auth', fn (Request $r) =>
    Limit::perMinute(5)->by($r->ip()));

Route::post('/login', [AuthController::class, 'login'])->middleware('throttle:auth');

CORS

// config/cors.php
'paths' => ['api/*', 'sanctum/csrf-cookie'],
'allowed_origins' => explode(',', env('CORS_ALLOWED_ORIGINS', '')), // explicit allowlist
'supports_credentials' => true, // required for Sanctum SPA auth
// NEVER ['*'] when credentials are supported

File Upload Security

public function rules(): array
{
    return [
        'document' => ['required', 'file', 'mimes:pdf,doc,docx', 'max:10240',
                       'extensions:pdf,doc,docx'],
        'avatar'   => ['nullable', 'image', 'mimes:jpg,jpeg,png,webp', 'max:2048',
                       'dimensions:max_width=2000,max_height=2000'],
    ];
}

Store sensitive files off the public disk and serve through an authorized, time-limited URL:

$path = $request->file('document')->store('documents', 'local'); // not 'public'

public function download(Request $request, string $path): RedirectResponse
{
    $this->authorize('download', $path);
    return redirect(Storage::temporaryUrl($path, now()->addMinutes(15)));
}

Secrets and Dependencies

composer audit          # run in CI; fail the build on advisories
# keep composer.lock committed; run composer update deliberately, never in CI

Read every secret from env()/config(); validate presence at boot. For production use a secret manager rather than a deployed .env.

Queue Security

// Encrypt sensitive payloads on the wire
final class ProcessPaymentJob implements ShouldQueue, ShouldBeEncrypted
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    public function __construct(
        private readonly string $paymentIntentId,
        private readonly string $cardFingerprint,
    ) {}

    public function handle(): void { /* ... */ }

    public function retryUntil(): \Carbon\CarbonInterface
    {
        return now()->addMinutes(5);
    }
}

Logging Security Events

// config/logging.php — dedicated 'security' channel
final class SecurityLogger
{
    public static function log(string $event, array $context = []): void
    {
        Log::channel('security')->warning($event, array_merge([
            'user_id' => Auth::id(),
            'ip'      => request()->ip(),
            'url'     => request()->fullUrl(),
        ], $context));
    }
}

SecurityLogger::log('failed_login_attempt', ['email' => $email]);
SecurityLogger::log('role_change', ['target_user' => $targetId, 'new_role' => 'admin']);

Quick Security Checklist

Laravel Security Audit

When auditing an existing Laravel application (instead of building new features), use @skills/laravel-security/references/audit-workflow.md. It covers the 7 audit areas — Authorization/IDOR/BOLA, Authentication, Validation, XSS, File upload, Secrets/configuration, Dependencies — with severity mapping (Critical/High/Medium/Low/Info → CR scale Critical/Moderate/Minor), Grep patterns, and a required regression-test sketch per confirmed finding. The building blocks in this file (Production Configuration, Authentication, Authorization, Eloquent Security, CSRF, XSS Prevention, Input Validation, File Upload Security, Secrets and Dependencies) are the reference fixes the audit workflow links back to.

Done when

• The relevant secure default is applied and matches the project's existing style
• No secret is hardcoded; required config/secrets are validated at boot
• Every applicable row of the checklist is satisfied or consciously waived
• Tests (Pest) cover the new auth/authorization/validation behavior

Related Skills

• @skills/security-review/SKILL.md — review workflow for existing code
• @skills/security-threat-analysis/SKILL.md — remediate a referenced advisory/CVE
• @skills/test-driven-development/SKILL.md — drive the implementation test-first