Vercel + PostgreSQL Security
Vercel's PostgreSQL offerings integrate tightly with your deployment. Learn how to secure these connections properly.
Why Vercel + PostgreSQL?
Vercel Postgres (powered by Neon) is the native choice for Next.js apps on Vercel. The tight integration requires understanding its security model.
Common Vulnerabilities
These are the security issues we find most often in Vercel apps using PostgreSQL.
Connection String in Client Code
Database connection strings may accidentally be exposed through NEXT_PUBLIC_ variables.
Missing RLS for Multi-Tenant Apps
PostgreSQL RLS is available but rarely configured in Vercel Postgres.
Preview Branch Database Access
Preview deployments may access production database if not configured properly.
Exposed via Server Actions
Server Actions may leak database data if not properly validated.
What We Check for Vercel + PostgreSQL
Environment Variable Security
Verify DATABASE_URL is not prefixed with NEXT_PUBLIC_.
Branch Database Configuration
Check that preview branches use isolated databases.
Server-Side Data Handling
Review Server Components and Actions for proper authorization.
Query Security
Check for SQL injection and proper parameterization.
Quick Security Wins
Apply these fixes right now to improve your security.
Remove NEXT_PUBLIC_ prefix from database variablesConfigure branch databases for preview deploymentsEnable RLS for multi-user applicationsUse parameterized queries with @vercel/postgresAdd authorization checks to all Server ActionsThe Bottom Line
Vercel + Postgres is secure when properly configured. Key points: keep connection strings server-side, use branch databases, and add RLS for multi-tenant apps.
Secure Your Vercel + PostgreSQL App
Find Row Level Security misconfigurations, exposed credentials, and other vulnerabilities before attackers do.
Start Security ScanFrequently Asked Questions
Is my Vercel Postgres connection string exposed?
Only if you accidentally use NEXT_PUBLIC_ prefix or include it in client components. DATABASE_URL should only be accessed in Server Components, Server Actions, and API routes. Vercel encrypts environment variables - they're not exposed unless you expose them in code.
Should I use branch databases for preview deployments?
Yes, especially for production apps. Vercel Postgres (Neon) supports branch databases - each preview deployment can have its own isolated database. This prevents preview builds from accessing or modifying production data.
Do I need RLS with Vercel Postgres?
For multi-user apps, yes. RLS provides database-level access control that works regardless of your application code. Even if there's a bug in your API, RLS ensures users can only access their own data. Enable it on all tables containing user data.
How do I prevent SQL injection with @vercel/postgres?
Use the sql template tag: sql`SELECT * FROM users WHERE id = ${userId}`. This automatically parameterizes the query. Never use string concatenation or template literals without the sql tag for database queries.