The most common security vulnerabilities in Vercel applications—and how to fix them before attackers find them.
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Common vulnerabilities found in Vercel applications
Secrets configured for Production but used in Preview, or vice versa.
Preview deployments may expose production secrets or fail with missing vars.
Compare environment variable scopes in Vercel dashboard.
Carefully configure scope for each variable: Development, Preview, Production.
No CSP, HSTS, X-Frame-Options configured.
XSS, clickjacking, and other client-side attacks more likely.
Check response headers in browser DevTools.
Add headers in next.config.js or vercel.json.
Preview URLs accessible without authentication, exposing unreleased features.
Pre-release features visible, possible preview-to-production data leak.
Check if preview URLs are accessible without Vercel account.
Enable Vercel Authentication for preview deployments.
console.log statements exposing secrets in function logs.
Anyone with log access can see sensitive data.
Review function code for console.log of sensitive variables.
Remove debug logging. Use proper secret management.
API routes allowing requests from any origin.
Cross-site request forgery, unauthorized API access.
Check Access-Control-Allow-Origin headers.
Restrict CORS to specific allowed origins.
Build logs may contain secrets echoed during build.
Secret exposure through build logs.
Review build logs for sensitive output.
Never echo secrets during build. Use Vercel secret management.
VAS scans your Vercel app for all these issues automatically. Free scan, instant results.
Scan Your App NowThe most common issues are: exposed API keys/secrets, missing database access controls (RLS or Security Rules), weak authentication configuration, and missing security headers. These account for over 80% of vulnerabilities in Vercel applications.
Run a VAS security scan for automated detection of common vulnerabilities. Manually check: database access controls, search code for hardcoded secrets, verify authentication settings, and test security headers. VAS catches all of these automatically.
Yes, nearly all Vercel security issues are configuration problems with straightforward fixes. Missing RLS, exposed secrets, weak auth—all have clear remediation steps. Most fixes take under an hour to implement.
Exposed databases and API keys can be discovered within minutes using automated scanners. Attackers actively scan for common patterns. This is why security configuration must happen before deployment, not after.
Vercel provides security features, but they require configuration. Security isn't automatic—you must enable database access controls, manage secrets properly, configure auth settings, and add security headers. The tools exist; you must use them.
Last updated: January 16, 2026