v0-generated apps are typically Next.js and React, which means they inherit the exact security defaults (or lack of them) that any hand-written Next.js app would have: no security headers unless you add them, and any secret referenced from client code ships to the browser. Because v0 is often used to scaffold a UI that's then wired to a real backend afterward, the biggest risk is usually in what gets connected after generation, not the generated code itself.
Why this happens in v0 apps
v0 generates polished, production-grade-looking React and Next.js components from a prompt. The visual and code quality being high doesn't imply the security configuration is: headers, secret handling, and backend access rules are a separate concern from component code.
Because v0's output often looks finished, it's easy to treat it as finished, including security hardening that was never actually part of the generation step.
Common issues in v0 apps
What tends to slip through:
- Missing security headers: a v0-generated Next.js app has no Content-Security-Policy, HSTS, or X-Frame-Options set unless you add them in next.config.js or middleware; v0 generates components, not deployment hardening.
- API keys wired in during the "connect a backend" step: once a generated UI is wired to a real API or database, it's common to paste a key into a client component to "get it working," especially inside a client-marked component v0 scaffolded for interactivity.
- Exposed source maps: default Next.js production builds emit source maps unless productionBrowserSourceMaps is explicitly set to false, handing out original, unminified source to anyone who requests the .map file.
How to fix it
Since the gap is usually in what happens after generation, focus there:
- Add headers() in next.config.js (CSP, HSTS, X-Frame-Options) as a standard step once a v0-generated project moves toward production.
- Whenever you wire a generated component to a real backend, route the credential through a server-side API route or Server Action instead of a client component.
- Set productionBrowserSourceMaps: false unless you have a specific reason to ship maps publicly.
Frequently asked
Does v0's generated code include any security review by default?
No. v0 focuses on generating UI components and app scaffolding. Headers, secret handling, and backend authorization are outside what the generation step produces or checks.
Is the risk different if I only use v0 for the frontend and write my own backend?
The frontend-only surface (headers, source maps, any accidentally-client-side secret) is the same either way. Your own backend's security is then entirely on your own review, same as any hand-written API.