Your v0 app looks production-ready. Is it actually secure?
v0 turns a prompt into a polished Next.js app you can push to Vercel the same day, and looking finished is not the same as being safe. The risk sits where you cannot see it: secrets marked NEXT_PUBLIC_ that get baked into the browser bundle, source maps that expose your server code, and database rules left open. Secrets leaking into public code is now the norm, GitGuardian found 28.6M secrets exposed on public GitHub in 2025. Veilguard scans your live v0 app, grades it A to F, and hands you the exact fix for every issue.
Looking done is not the same as being safe
v0 is exceptional at generating interfaces, and that polish is exactly what hides the risk: an app that looks finished reads as safe. But the security-critical parts, who is allowed to do what, and which secrets reach the browser, are decisions v0 makes for convenience, not safety.
It is a broad pattern, not a v0 quirk. Veracode’s 2025 study found AI writes insecure code about 45% of the time. A confident, good-looking result is not evidence the access rules and secrets are handled correctly.
Where v0 apps leak
- Secrets in the bundle: keys marked NEXT_PUBLIC_ (or otherwise shipped to the client) are one right-click away from anyone.
- Exposed source maps: production source maps that hand an attacker your server logic and structure.
- Open database rules: Supabase RLS or Postgres policies left permissive, so any visitor can read or change data that is not theirs.
- Unprotected server actions and routes: Next.js server actions and API routes that skip authorization, letting the wrong user trigger privileged operations.
- Unsigned payment webhooks and open CORS: forged events marked as paid, and APIs that answer any origin.
Keep v0’s secrets on the server
- 1.Only prefix a variable with NEXT_PUBLIC_ if it is genuinely safe to publish; keep every real secret in server-only env and read it in server actions or route handlers.
- 2.Disable production source maps so your server logic is not shipped to the browser.
- 3.Turn on database rules (Supabase RLS or Postgres policies) and scope each user to their own rows.
- 4.Add an authorization check at the top of every server action and API route, from the verified session.
- 5.Verify Stripe webhook signatures on the server, lock CORS to your domain, and re-scan after each deploy.
Get the secrets out of the bundle
Paste your deployed URL into Veilguard and it scans your live v0 app from the outside in about a minute, flagging keys and source maps exposed in the browser. Connect GitHub read-only to also check for authorization gaps in your server actions and routes. Every finding comes with copy-paste code or a prompt you can hand back to v0.
Frequently asked
Can Veilguard scan a v0 (Vercel) app?
Yes. Paste your deployed URL and we scan it from the outside in about a minute. If it uses Supabase, we run a deeper row-level-security audit as well.
What does NEXT_PUBLIC_ actually expose?
Any variable prefixed with NEXT_PUBLIC_ is inlined into the JavaScript sent to every visitor’s browser, so it is effectively public. If a real secret (a service_role key, a Stripe secret, an API token) ends up there, anyone can read it from your page. Keep those server-side only.
Does it check Next.js server actions and API routes?
With a read-only GitHub connection we check for authorization gaps in server actions and routes, a common way v0 apps let the wrong user do privileged things.
How are the fixes delivered?
As copy-paste code or a ready-made prompt you can hand back to v0. You do not need to understand the code to apply them.
