Is v0 (Vercel) safe?
v0 is Vercel's vibe-coding tool. Here is how its output differs from other vibe platforms security-wise and what to verify before shipping.
v0 generates Next.js components that are generally well-structured for security — but the same Next.js pitfalls apply: middleware matcher gaps, missing auth on server actions, BOLA on dynamic routes. Vibe Leak Index: ~11% leak rate (lowest of the four major platforms).
How it fails in production
Dynamic routes without ownership checks
v0 generates `/[id]` routes that fetch by ID without verifying ownership — classic BOLA.
Server actions without session guard
v0 uses Server Actions heavily; auth checks are not consistently added.
Middleware matcher gaps
Routes that should be gated by middleware sometimes live outside the matcher glob.
How to ship safely on v0 (Vercel)
- Review every /[id] route for ownership checks
- Add a session check at the top of every server action
- Verify middleware matcher covers all protected routes
- Run a scan on the deployed preview before promoting to production
Securie's BOLA specialist + Server Action auth checker + middleware matcher analyzer all fire on v0 output.
Verdict
v0 is the safest of the major vibe-coding platforms at launch — but 'safest' is still far from 'safe'.