Is Cursor AI Code Secure? What We Found Auditing 20+ Cursor Projects

grep -r "sk_live\\|sk_test\\|SUPABASE_SERVICE_ROLE" --include="*.tsx" --include="*.ts" src/

Why this matters for ecommerce: An exposed Stripe secret key lets an attacker issue refunds, create charges, and access your entire payment history. One exposed key cost a Shopify store owner $23,000 in fraudulent refunds before they noticed.

2. Missing Server-Side Input Validation

What this looks like: Form inputs, search queries, and API parameters pass directly to database queries or backend functions without sanitization.

How common: Found in 17 of 20 projects (85%).

Why Cursor does this: Cursor generates clean-looking code that accepts user input and passes it through. The generated code handles the happy path — valid email addresses, expected product IDs, normal search terms. It rarely generates validation for malicious input because AI training data skews toward functional examples, not adversarial ones.

The fix: Add input validation at the server level — never trust client-side validation alone. For Next.js projects (common with Cursor), use a validation library like Zod on every API route:

// Before: Cursor's generated code

const { email } = req.body;

await db.users.findByEmail(email);

// After: Validated

const schema = z.object({ email: z.string().email() });

const { email } = schema.parse(req.body);

await db.users.findByEmail(email);

Why this matters for ecommerce: Unvalidated input on checkout forms can lead to price manipulation. We found one Cursor-built store where modifying the request body allowed changing the order total — customers could pay $1 for a $500 product.

3. Broken Authentication and Session Management

What this looks like: Authentication tokens stored in localStorage (instead of httpOnly cookies), no session expiration, missing CSRF protection, and auth checks only on the frontend.

How common: Found in 15 of 20 projects (75%).

Why Cursor does this: Cursor generates the simplest authentication pattern that works. LocalStorage is the easiest way to persist a token. Client-side auth checks are the fastest way to show/hide UI elements. Neither is secure — localStorage is accessible to any JavaScript running on your page (including injected scripts), and client-side auth checks can be bypassed by modifying the browser's JavaScript.

The fix: Move authentication tokens to httpOnly, Secure, SameSite cookies. Add server-side middleware that validates the session on every protected route — not just on the frontend. For Next.js:

// middleware.ts — runs on every request

export function middleware(request: NextRequest) {

const session = request.cookies.get('session');

if (!session && request.nextUrl.pathname.startsWith('/admin')) {

return NextResponse.redirect(new URL('/login', request.url));

}

}

Why this matters for ecommerce: Broken auth in an online store means attackers can access other customers' accounts, view order histories with addresses and phone numbers, and potentially make purchases using saved payment methods.

4. Overly Permissive Database Access

What this looks like: Supabase or database configurations with no Row Level Security (RLS), service role keys used in client-side code, and queries that return all columns including sensitive fields.

How common: Found in 14 of 20 projects (70%).

How to check: If you're using Supabase, run this in the SQL editor:

SELECT tablename FROM pg_tables

WHERE schemaname = 'public'

AND tablename NOT IN (

SELECT tablename FROM pg_tables t

JOIN pg_policies p ON t.tablename = p.tablename

);

Any tables in the result have no RLS policies — they're wide open.

The fix: Enable RLS on every table and create policies that restrict access. Never use the Supabase service role key in client-side code. Select only the columns you need:

-- Instead of: SELECT * FROM orders

SELECT id, product_name, quantity, total, status FROM orders

WHERE user_id = auth.uid();

Why this matters for ecommerce: Without RLS, every customer can potentially see every other customer's orders, addresses, and purchase history. This is a GDPR violation in the EU and a data breach in every jurisdiction.

5. No Security Headers or HTTPS Enforcement

What this looks like: Missing Content-Security-Policy, X-Frame-Options, Strict-Transport-Security headers. No HTTPS redirect on HTTP requests. Missing rate limiting on authentication endpoints.

How common: Found in 19 of 20 projects (95%).

Why Cursor does this: Cursor focuses on generating application code, not deployment configuration. Security headers are typically set at the server/CDN level, not in application code. Because they're "invisible" — the app looks and works the same without them — they're consistently overlooked.

How to check:

curl -I https://yourdomain.com | grep -i "strict-transport\\|content-security\\|x-frame\\|x-content-type"

If none of these headers appear, your site is missing basic security protections.

Strict-Transport-Security: max-age=31536000; includeSubDomains

Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline'

X-Frame-Options: DENY

X-Content-Type-Options: nosniff

Why this matters for ecommerce: Without CSP headers, attackers can inject payment skimmers (Magecart-style attacks). Without HSTS, customers can be redirected to a fake version of your checkout page. These aren't theoretical — e-commerce card skimming attacks increased 174% in 2025.

Beyond the Code: Cursor's Own Security Track Record

The security concerns aren't limited to code Cursor generates. The IDE itself has had multiple critical vulnerabilities disclosed in 2025:

These are vulnerabilities in the *tool itself*, separate from the insecure code it generates. Cursor's own security page states that enabling Workspace Trust — which would mitigate some of these risks — "disables AI and other Cursor features." Security and full functionality are literally presented as a tradeoff.

For ecommerce founders, this means two attack surfaces: the code Cursor generates AND the environment you're generating it in. If you're building a store that handles payment data, both surfaces need protection.

The 5-Point Security Hardening Checklist

After auditing 20+ Cursor projects, here's the minimum security check every ecommerce project needs: