v0
Security FAQ

What are common security mistakes in v0.dev apps?

Get instant answers about your app's security.

Short Answer

The mistakes we see repeatedly in v0.dev apps: xss via dangerouslysetinnerhtml; missing input validation; placeholder api calls. Each one is a specific failure mode of v0.dev's workflow — not generic programming mistakes.

Detailed Answer

The mistakes we actually see in v0.dev apps

These aren't hypothetical — they're what VAS finds when it scans a v0.dev app for the first time. Listed in order of how often they appear:

1. XSS via dangerouslySetInnerHTML

*Why it happens:* AI may suggest React patterns that render unsanitized user content.

*Fix:* Search for dangerouslySetInnerHTML. Sanitize all dynamic HTML with DOMPurify.

2. Missing Input Validation

*Why it happens:* v0 generates UI but not server-side validation logic.

*Fix:* Add server-side validation for all form inputs. Never trust client-side only.

3. Placeholder API Calls

*Why it happens:* Generated code may include placeholder URLs or fake endpoints.

*Fix:* Review all fetch/API calls. Replace placeholders before deployment.

4. Client-Side Auth Patterns

*Why it happens:* UI-only auth flows that can be bypassed.

*Fix:* Implement real auth with NextAuth.js, Clerk, or Supabase Auth.

5. Outdated Dependencies

*Why it happens:* Suggested packages may have known vulnerabilities.

*Fix:* Run npm audit after installation. Update vulnerable packages.

Why these specifically show up in v0.dev (and not as much elsewhere)

v0.dev's workflow optimizes for speed — idea to deployed app in minutes. The mistakes above aren't character flaws, they're the predictable output of a speed-optimized workflow that doesn't enforce security gates. The fix is treating security gates as non-negotiable, not as "I'll get to it later."

Security Research & Statistics

10.3%

of Lovable applications (170 out of 1,645) had exposed user data in the CVE-2025-48757 incident

Source: CVE-2025-48757 security advisory

4.45 million USD

average cost of a data breach in 2023

Source: IBM Cost of a Data Breach Report 2023

500,000+

developers using vibe coding platforms like Lovable, Bolt, and Replit

Source: Combined platform statistics 2024-2025

Expert Perspectives

There's a new kind of coding I call 'vibe coding', where you fully give in to the vibes, embrace exponentials, and forget that the code even exists.

Andrej KarpathyFormer Tesla AI Director, OpenAI Co-founder

It's not really coding - I just see stuff, say stuff, run stuff, and copy paste stuff, and it mostly works.

Andrej KarpathyFormer Tesla AI Director, OpenAI Co-founder

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More Questions About This Topic

How common are these mistakes in v0.dev apps — is this overstated?

Understated, if anything. The majority of v0.dev apps scanned for the first time have at least one of the high-likelihood mistakes above. "XSS via dangerouslySetInnerHTML" in particular is the default state of a new v0.dev app before any security work. Our sample skews toward apps whose owners care enough to scan — the base rate for never-scanned v0.dev apps is higher.

What are the actual consequences when these mistakes ship to production?

The consequence ladder: (a) data exposure — emails, passwords, PII, payment info readable by anyone; (b) account takeover — if auth is weak, legitimate accounts get hijacked; (c) third-party abuse — an exposed OpenAI or Stripe key gets drained of quota or money; (d) regulatory — GDPR/CCPA notification requirements trigger at ~first exposure; (e) reputational — "v0.dev app data breach" is a headline that doesn't age well. Each consequence compounds the next.

How do I avoid these mistakes when building with v0.dev?

Three non-negotiable habits: (1) Configure Row Level Security (RLS) policies at table/collection creation — before writing any feature code. (2) Treat any paste-a-key-into-code as a bug from the first keystroke, not "I'll move it to env vars later." (3) Run a VAS scan before every production deploy — five minutes of scanning prevents hours-to-weeks of breach response. Specifically: Search for dangerouslySetInnerHTML. Sanitize all dynamic HTML with DOMPurify..