Vibe Coding and MVP Security: What to Review Before Launch

Security is one of the areas vibe coding is least likely to get right by default — not because AI tools are careless, but because security requirements are rarely part of what a prompt actually asks for. “Build a signup form” doesn’t include “and make sure one user can’t see another user’s data,” so unless someone specifically checks for it, it often isn’t handled. This is a practical rundown of what to review before a vibe-coded MVP goes live.

Why Security Gets Missed in Vibe-Coded Builds

AI coding tools generate code that satisfies the literal request in front of them. They’re very good at producing a working feature and considerably less consistent at anticipating the ways that feature could be misused or attacked, unless the prompt explicitly asks for it. Combine that with prompt-by-prompt development across many separate sessions, and security gaps end up distributed unevenly across the product — solid in one area, missing in another, with no single review that ever looked at the whole picture.

This isn’t a reason to avoid vibe coding. It’s a reason to treat security as a deliberate, separate pass rather than something that happens automatically alongside feature-building.

Access Controls: Who Can See and Do What

This is the most common gap, and the hardest one to spot from a single-user demo.

• Confirm a logged-in user genuinely cannot view or edit another user’s data by changing a URL or an ID in a request.
• Check that admin-only actions are actually restricted server-side, not just hidden in the interface — a hidden button isn’t a security control.
• Test what happens when someone tries to access a page or resource they shouldn’t be able to reach directly.

Data Handling: What’s Stored, and How

• Confirm passwords are hashed, not stored in plain text — this should be table stakes but is worth verifying directly rather than assuming.
• Check that sensitive fields (payment details, personal identifiers) are encrypted appropriately, or better yet, handled by a specialized third-party provider rather than stored directly.
• Verify user data can be exported or deleted on request, which matters both for trust and for basic data protection compliance.

Secrets and Configuration

• Search the codebase for hardcoded API keys, database credentials, or tokens — a genuinely common leftover from fast prompting sessions.
• Confirm environment variables are used for anything sensitive, and that they’re not committed to version control.
• Check that development and production environments use separate credentials and separate databases.

Dependencies

• Review the third-party packages the AI tool pulled in — some may be unnecessary, outdated, or poorly maintained.
• Remove anything that isn’t actually being used; every dependency is a piece of code you didn’t write but are still responsible for.
• Check for known vulnerabilities in the dependencies you’re keeping using standard tooling for your stack.

The OWASP Top Ten is a useful, non-product-specific reference for this kind of review — it’s the industry-standard list of the most common web application security risks, and most of the gaps above map directly onto it.

A Quick Reference Table

Area	What to check	Why it’s missed by default
Access controls	Users can’t reach others’ data or admin actions	Only surfaces with multi-user testing
Data handling	Passwords hashed, sensitive fields encrypted	Not visible from the UI
Secrets	No hardcoded keys or credentials	Convenient during fast prompting
Dependencies	No outdated or unnecessary packages	Rarely reviewed once a feature “works”

Where This Fits Into a Broader Pre-Launch Review

Security is one part of a wider pre-launch process, not the whole of it. If you haven’t yet worked through the rest — product testing, legal basics, deployment hardening — the full pre-launch checklist for vibe-coded MVPs covers those alongside security. And if the underlying concern is really about whether the codebase overall is trustworthy, not just secure, a broader code review is the next logical step.

What to Do If This Review Finds Problems

Finding gaps in this review isn’t a sign the MVP needs to be scrapped — it’s the review doing its job. Prioritize by exposure: anything touching authentication, payments, or another user’s data goes first. Anything in a low-traffic, low-risk area can reasonably wait. The goal is closing the highest-risk gaps before real users are exposed to them, not achieving a perfect security posture before anyone can sign up.

An Example of How This Plays Out

Consider a simple marketplace MVP where users can list items for sale. A prompt like “let a user create a listing and view their own listings” gets implemented correctly — a user sees exactly their own listings, nothing more. But a related prompt, added later, for “let a user edit a listing” is implemented by directly accepting a listing ID from the request and updating it, without re-checking that the listing actually belongs to the user making the request. In a single-user demo, this never surfaces, because the person testing it only ever edits their own listings. It only becomes visible — or exploitable — once a second user tries changing the ID in the request and discovers they can edit someone else’s listing.

This is a textbook access control gap, and it’s exactly the kind of thing that’s invisible until specifically tested for, because the feature “works” from every angle a normal demo would check. It’s also exactly why access control deserves the dedicated, deliberate review outlined above rather than being assumed to follow naturally from the fact that login is required somewhere in the flow.

How Often This Kind of Review Needs to Happen

A single pre-launch security pass isn’t a permanent guarantee — each new feature added after launch reopens the same category of risk, particularly for anything touching data ownership or admin actions. Treating security review as a recurring habit tied to feature releases, rather than a one-time checklist completed before the first launch, is what keeps a product’s security posture from quietly eroding as new prompts and new features get added over time. This doesn’t need to be a heavyweight process for a small MVP — even a short, consistent check against the areas above each time a significant new feature ships covers most of the risk.

The Bottom Line

Vibe-coded MVPs aren’t insecure by default because AI writes bad code — they’re insecure by default because security isn’t automatically part of what a prompt asks for. A focused review of access controls, data handling, secrets, and dependencies closes most of the gap before real users show up, and it’s a matter of days, not a second build.

Frequently Asked Questions

Is AI-generated code inherently less secure than hand-written code?

Not inherently, but it's unverified by default. AI tools optimize for producing code that satisfies the prompt, not for anticipating security risks the prompt didn't mention — so security needs to be checked deliberately rather than assumed.

What's the single most common security gap in vibe-coded MVPs?

Weak or missing access controls — code that lets a logged-in user technically reach or modify another user's data because no prompt explicitly said to prevent it. This is easy to miss in a demo since testing is usually done as a single user.

Do I need a formal security audit before launching a small vibe-coded MVP?

A formal third-party audit isn't always necessary for an early-stage MVP, but a focused internal review against a checklist like this one is close to the minimum bar before real user data or payments are involved.

Are third-party AI-generated dependencies a security risk?

They can be, if packages were added quickly during prompting sessions without review. Outdated or unnecessary dependencies are a common, easily overlooked source of vulnerabilities in fast-built products.