Guides16 min read

Security Checklist for Lovable Apps: 15 Things to Check Before Launch

The complete security checklist for non-technical founders building with Lovable. 15 actionable checks with AI fix prompts you can copy-paste.

H

HackNope Team

January 4, 2026

A security checklist with checkmarks protecting a Lovable app - showing the 15 essential security checks every founder needs before launch

You've built something amazing with Lovable. Users are signing up. But before you celebrate, let's make sure hackers aren't celebrating too.

Here's the security checklist I wish every Lovable founder had before launch.

Why Lovable Apps Need a Security Check

Lovable is fantastic for building fast. It handles your hosting, SSL certificates, and basic infrastructure. You can go from idea to deployed app in hours.

But here's the thing: Lovable builds what you tell it to build. If you don't ask for security features, you won't get them.

Heads up

Common misconception: "My app works fine, so it must be secure." Security vulnerabilities don't show up as errors—they hide until someone exploits them.

Your business logic, how users access data, where API keys are stored—that's all YOUR responsibility. And that's exactly what attackers target.

Let's fix it with 15 specific checks you can do today.

The 15-Point Security Checklist

Each item includes what to check, why it matters, how to check it, and an AI fix prompt you can paste into Lovable or your AI coding assistant.

Authentication & Access

1. Secure Authentication Setup

What to check: Your Supabase Auth or authentication provider is properly configured with secure session handling and reasonable password requirements.

Why it matters: Weak authentication is the #1 way attackers get into accounts. If your login can be brute-forced or sessions last forever, you're exposed.

How to check:

  1. Try signing up with a weak password like "123456"—does it allow it?
  2. Check if sessions expire after inactivity
  3. Test password reset flow—do tokens expire?
  4. Look for rate limiting on login attempts

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Review my Lovable app's authentication setup. Check for:

  1. Password requirements (minimum 8 characters, mix of letters and numbers)
  2. Rate limiting on login attempts (max 5 attempts per minute)
  3. Secure session handling with proper expiration (24 hours max)
  4. Password reset tokens that expire after 1 hour
  5. Secure cookie settings (httpOnly, secure, sameSite)

Show me the current configuration and fix any issues.

2. Authorization on All Protected Routes

What to check: Users can ONLY access their own data. User A cannot see User B's profile, orders, or settings.

Why it matters: This is the most common vulnerability we see. Everything looks fine when you test your own account, but there's nothing stopping users from accessing each other's data.

Critical Risk

Immediate action required

If a user can change the ID in a URL and see someone else's data, you have a critical authorization flaw. This could leak all your user data.

How to check:

  1. Log in as User A, note the URL of your profile/dashboard (e.g., /profile/123)
  2. Log out and log in as User B (create a second test account)
  3. Manually type User A's URL—can User B see User A's data?
  4. Repeat for API calls in your network tab

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Add authorization checks to ensure users can only access their own data. For every database query and API endpoint:

  1. Verify the authenticated user's ID matches the resource owner
  2. Never trust user-provided IDs without verification
  3. Return 404 (not 403) for unauthorized access to prevent enumeration
  4. Add server-side checks, not just UI hiding

Show me all routes that need authorization fixes and implement them.

3. No Hardcoded Admin Credentials

What to check: No admin passwords, test accounts, or backdoors are hardcoded in your codebase.

Why it matters: Attackers can read your source code. Hardcoded credentials are like leaving your house key under the doormat with a sign pointing to it.

How to check:

  1. Search your codebase for: password, admin, secret, test@, 1234
  2. Check for any commented-out login bypasses
  3. Look for if (user.email === "admin@") type conditions

Warning

We've seen production apps with if (password === "admin123") checks. These are found within minutes by automated scanners.

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Search my entire codebase for hardcoded credentials, secrets, or backdoors. Look for:

  1. Hardcoded passwords or admin credentials
  2. Test account bypasses
  3. Debug mode checks that skip authentication
  4. Commented-out security checks
  5. Email or password comparisons against hardcoded strings

Remove any found and replace with proper environment variables or authentication flows.

API & Data Security

4. API Keys in Environment Variables

What to check: No API keys, tokens, or secrets are visible in your frontend JavaScript code.

Why it matters: Frontend code is visible to everyone. If your OpenAI key is in browser code, anyone can use it—and you pay the bill.

Critical Risk

Immediate action required

Exposed API keys can be found in seconds using browser DevTools. Attackers have bots that scan for these automatically.

How to check:

  1. Open your deployed app in Chrome
  2. Right-click → View Page Source
  3. Press Ctrl+F and search for: sk-, key, api, token, secret
  4. Also check the Network tab for API calls containing keys
  5. Check browser console for any logged secrets

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Move all API keys from frontend code to environment variables and server-side only access. Specifically:

  1. Find all API keys, tokens, and secrets in frontend code
  2. Move them to .env.local (for development) and Vercel/hosting environment variables
  3. Create server-side API routes that use these keys
  4. Update frontend to call your server routes instead of external APIs directly

List every key you find and show me the migration plan.

5. Server-Side API Calls for Sensitive Operations

What to check: Payments, authentication, and data modifications happen on the server, not in browser JavaScript.

Why it matters: Anything in the browser can be manipulated. If payment validation happens client-side, users can modify it to pay $0.

How to check:

  1. Open DevTools → Network tab
  2. Complete a payment or sensitive action
  3. Check if the API calls go directly to Stripe/external services or to your backend first
  4. If you see direct calls to payment providers with client-side amounts, that's a problem

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Ensure all sensitive operations happen server-side:

  1. Payment processing - amounts must be calculated server-side, not passed from client
  2. Authentication checks - verify sessions on server, not just in browser
  3. Data validation - validate all input on server before database operations
  4. Authorization - check permissions server-side before any data access

Show me which operations are currently client-side that should be server-side.

6. Input Validation on All Forms

What to check: Forms reject malicious input and validate data types, lengths, and formats.

Why it matters: Without validation, attackers can inject scripts, SQL commands, or corrupt your data.

How to check:

  1. Find any text input field in your app
  2. Enter: <script>alert('xss')</script>
  3. Submit and see if the script executes or is stored/displayed
  4. Also try: '; DROP TABLE users; -- in search or filter fields

Heads up

If you see an alert popup when testing XSS, your app is vulnerable. Any input that's stored and displayed to other users could run malicious code.

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Add comprehensive input validation and sanitization to all form fields:

  1. Validate email formats, phone numbers, and expected data types
  2. Set reasonable maximum lengths on all text fields
  3. Sanitize HTML to prevent XSS (use a library like DOMPurify)
  4. Use parameterized queries for any database operations
  5. Add server-side validation (don't rely only on frontend checks)

Show me each form and the validation rules to add.

7. Database Rules Properly Configured

What to check: Supabase Row Level Security (RLS) policies are enabled and correctly configured.

Why it matters: Without RLS, anyone with your Supabase URL can query your entire database. RLS is your last line of defense.

Critical Risk

Immediate action required

RLS is disabled by default on new Supabase tables. If you didn't explicitly enable it, your data may be publicly readable.

How to check:

  1. Log into Supabase dashboard
  2. Go to Authentication → Policies
  3. Check each table—is RLS enabled (toggle should be ON)?
  4. Review each policy—do they correctly limit access to authenticated users' own data?

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Review and configure Supabase Row Level Security for all tables:

  1. Enable RLS on every table (it's off by default)
  2. Create policies that allow users to only SELECT their own data (where user_id = auth.uid())
  3. Add INSERT policies that set user_id automatically from auth.uid()
  4. Add UPDATE and DELETE policies limited to own data
  5. For admin tables, create separate admin-only policies

Show me each table's current RLS status and the policies to add.

Security Headers & Configuration

8. Security Headers Enabled

What to check: Your app sends proper security headers like Content-Security-Policy and X-Frame-Options.

Why it matters: These headers prevent XSS attacks, clickjacking, and other browser-based exploits. They're your first line of defense.

How to check:

  1. Go to securityheaders.com
  2. Enter your app's URL
  3. Check your grade—aim for at least B, ideally A

Good to know

Most Lovable apps score D or F on security headers out of the box. Adding headers can bump you to an A in minutes.

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Add security headers to my Lovable app. I need:

  1. Content-Security-Policy (CSP) - restrict script sources
  2. X-Frame-Options: DENY - prevent clickjacking
  3. X-Content-Type-Options: nosniff - prevent MIME sniffing
  4. Strict-Transport-Security - enforce HTTPS
  5. Referrer-Policy: strict-origin-when-cross-origin
  6. Permissions-Policy - disable unnecessary browser features

Configure these as middleware or in the appropriate config file.

9. HTTPS Everywhere

What to check: All connections use HTTPS, with no mixed content warnings.

Why it matters: HTTP connections can be intercepted and modified. HTTPS encrypts everything in transit.

How to check:

  1. Look at your browser's address bar—there should be a padlock icon
  2. Open DevTools → Console, look for "Mixed Content" warnings
  3. If using a custom domain, verify HTTPS is properly configured

Pro tip

Lovable handles HTTPS automatically for their default domains. But if you've added a custom domain, verify SSL is configured correctly.

10. Debug Mode Disabled

What to check: No debug information, stack traces, or verbose errors are visible in production.

Why it matters: Debug info tells attackers exactly how your app works, what database you use, and where vulnerabilities might be.

How to check:

  1. Trigger an error intentionally (enter invalid data, visit a wrong URL)
  2. Check if you see technical error messages, stack traces, or file paths
  3. Look in browser console for development warnings or logs

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Ensure debug mode is disabled in production:

  1. Remove or conditionally hide all console.log statements
  2. Set up proper error boundaries that show user-friendly messages
  3. Configure error logging to go to a service like Sentry, not the browser
  4. Ensure NODE_ENV is set to "production" in deployment
  5. Remove any development-only routes or features

Show me where debug info might be leaking and how to fix it.

Business Logic Security

11. Paywall Cannot Be Bypassed

What to check: Premium features are enforced server-side, not just hidden in the UI.

Why it matters: If you only hide premium features in CSS/JavaScript, users can access them by modifying browser code. Your revenue depends on server-side enforcement.

High Risk

Fix as soon as possible

We've seen apps where premium features were just hidden with CSS. A single line in DevTools unlocked everything. That's $0 revenue from tech-savvy users.

How to check:

  1. As a free user, open DevTools → Elements
  2. Search for premium features in the DOM—are they rendered but hidden?
  3. Check Network tab—can you call premium API endpoints without a paid subscription?
  4. Try modifying local storage or cookies that might store subscription status

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Ensure premium features are protected server-side:

  1. Check subscription status on the server for every premium API endpoint
  2. Don't render premium UI at all for free users (not just hide it)
  3. Store subscription status in your database, not in local storage
  4. Add middleware that validates subscription before processing premium requests
  5. Return proper 403 errors when non-subscribers try to access premium features

Show me where subscription checks are missing and implement server-side validation.

12. Rate Limiting on Critical Endpoints

What to check: Login, signup, password reset, and API endpoints have request limits.

Why it matters: Without rate limiting, attackers can try thousands of passwords per second or overwhelm your app with requests.

How to check:

  1. Try logging in with wrong password 20 times quickly
  2. Does the app slow you down or block you?
  3. Try submitting a form repeatedly—is there any limit?

Heads up

A single attacker can try 10,000 passwords per hour without rate limiting. With rate limiting, that drops to maybe 60. That's the difference between minutes and centuries to crack a password.

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Add rate limiting to protect critical endpoints:

  1. Login: max 5 attempts per minute per IP
  2. Signup: max 3 signups per minute per IP
  3. Password reset: max 3 requests per hour per email
  4. API endpoints: appropriate limits based on expected usage
  5. Add exponential backoff for repeated failures

Use a library like rate-limiter-flexible or implement with Redis. Show me the implementation.

13. File Uploads Validated

What to check: Only allowed file types are accepted, and file sizes are limited.

Why it matters: Malicious files can execute code on your server, contain viruses, or fill up your storage.

How to check:

  1. Find any file upload in your app
  2. Try uploading a .exe, .php, or .html file (rename if needed)
  3. Try uploading a very large file (100MB+)
  4. Check if uploaded files can be accessed directly via URL

High Risk

Fix as soon as possible

If attackers can upload executable files to your server and access them via URL, they can run arbitrary code. This can compromise your entire system.

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Add file upload validation and security:

  1. Validate file types by content (magic bytes), not just extension
  2. Only allow specific MIME types (e.g., image/png, image/jpeg, application/pdf)
  3. Set maximum file size limits (e.g., 5MB for images)
  4. Rename uploaded files to prevent path traversal
  5. Store uploads outside the webroot or in a cloud storage service
  6. Scan uploaded files for malware if possible

Show me current upload handling and add proper validation.

Monitoring & Response

14. Error Handling Doesn't Leak Info

What to check: Error messages are user-friendly and don't reveal technical details.

Why it matters: "Database error: connection to postgresql://user:password@localhost failed" tells attackers your database type, username, and that it's local. "Something went wrong" tells them nothing.

How to check:

  1. Trigger various errors: invalid input, wrong URLs, network issues
  2. Check the error messages shown—are they generic or technical?
  3. Look at the browser console for leaked stack traces

AI Fix Prompt

Copy to Cursor, Claude Code, or Copilot

Implement proper error handling that doesn't leak sensitive information:

  1. Create generic user-facing error messages ("Something went wrong. Please try again.")
  2. Log detailed errors server-side only (to Sentry, LogRocket, or a logging service)
  3. Never expose database errors, stack traces, or file paths to users
  4. Return appropriate HTTP status codes without verbose bodies
  5. Add error boundaries in React to catch and handle frontend errors gracefully

Show me where errors might leak info and implement safe error handling.

15. You Have a Response Plan

What to check: You know what to do if you get breached—who to contact, how to take the app offline, and how to notify users.

Why it matters: When a breach happens (and they do), speed matters. Hours of confusion can turn a minor incident into a catastrophe.

What you need:

  1. Emergency contacts: Your hosting provider's security email, Supabase support, and your own emergency phone tree
  2. Shutdown procedure: How to take your app offline quickly if needed
  3. User notification: Template email ready for breach notification
  4. Backup access: How to restore from backups if data is corrupted
  5. Legal requirements: Know your obligations (GDPR, CCPA breach notification requirements)

Good to know

You don't need a 50-page incident response plan. Even a simple document with emergency contacts and steps is infinitely better than nothing.

How to Use This Checklist

Don't try to fix everything at once. Here's the approach:

  1. Go through systematically - Check each item one by one
  2. Fix critical items first - Items 1, 2, 4, 7, and 11 are your highest priority (the ones marked with critical/high risk)
  3. Document what you've checked - Keep a record for your own peace of mind
  4. Re-check after major updates - Any significant feature could introduce new vulnerabilities
  5. Consider automated scanning - Tools like HackNope can catch issues you might miss

What Lovable Handles vs What You Handle

This is the key insight most founders miss. Let's be crystal clear:

Lovable Handles

  • SSL/HTTPS - All connections are encrypted
  • Hosting security - Servers are patched and maintained
  • Infrastructure patches - Operating system and runtime updates
  • Basic DDoS protection - Traffic spikes won't immediately crash you

You Handle

  • Authorization logic - Who can access what data
  • API key management - Keeping secrets secret
  • Business logic security - Paywalls, subscriptions, user permissions
  • Data access controls - Supabase RLS and database security
  • Input validation - Preventing injection attacks in your components
  • Rate limiting - Protecting against brute force

Heads up

The "you handle" list is where 90% of breaches happen. These aren't infrastructure problems—they're logic problems in the code you told Lovable to build.

What to Do Next

You've got the checklist. Now take action:

  1. Run a free scan - Get a security report from HackNope in plain English
  2. Fix critical issues first - Use the AI prompts above with Lovable or your AI assistant
  3. Bookmark this page - Come back before every launch
  4. Set up monitoring - Get alerted when something suspicious happens

Security isn't a one-time fix—it's an ongoing practice. But with this checklist, you're already ahead of 90% of vibe-coded apps out there.

Now go make your app bulletproof.

Frequently Asked Questions

H

Written by

HackNope Team

The HackNope team helps non-technical founders secure their vibe-coded apps.

#lovable#security-checklist#no-code#vibe-coding#supabase#launch-checklist
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