v0 is strong at generating clean React and Next.js code. The security gaps show up not in the components but at the seams: where the frontend talks to a backend, where environment variables get read, and where an API route forgets to check who is calling.
What tends to go wrong in v0 and Next.js apps
- Secrets accidentally exposed through a NEXT_PUBLIC environment variable
- API routes and server actions without an authentication or authorization check
- Supabase access shipped to the client without Row Level Security
- JWTs decoded without verifying the signature
The NEXT_PUBLIC trap is especially easy to hit: anything with that prefix is bundled into the browser. We cover it in why NEXT_PUBLIC variables leak.
Scan your own app for issues like these
Paste your live URL. We check what your app serves publicly for exposed keys and misconfigurations. No account, no install.
The fastest check
Run a free scan on your v0 app repo or live URL for a prioritized list of findings with exact file and line. It catches the exposed key, the unguarded route, and the decode-without-verify bug before your users do.