Vibe coding without security: the Mayumi case and what your AI won't tell you about the backend

In early June 2026, streamer Mayumi announced with great fanfare the launch of Kippu, a platform built to be a Brazilian alternative to OnlyFans and Privacy. During the campaign, she publicly criticized how fragile her competitors' backends were — and assured everyone that her team of engineers had built something genuinely solid. Hours after going live, the internet proved otherwise.

A hacker accessed Kippu's API and exposed sensitive data belonging to every registered user: full names, emails, phone numbers, and addresses. No password needed, no token needed, no actual break-in needed. The API worked perfectly — it just had no locks on it at all. The platform went offline, accounts were deleted, and refunds were processed in a rush. The technical community reacted with immediate suspicion: this looked like pure vibe coding — an entire project generated by AI with no security review whatsoever.

Host Peter, from the channel Nerds de Negócios, dedicated an entire video to the case and summed it up precisely: AI is excellent at building beautiful interfaces, but it completely ignores the invisible protocols of security. That's exactly what any independent developer needs to hear before publishing their own app.

What actually happened

Kippu failed at the three most basic principles of application security: authentication, authorization, and access control. The API was there, it answered requests, and it returned data — but anyone, without logging in, could look up any user's information. It was like building a house with glass walls and being surprised that everyone can see inside.

The classic mistake the case exposes is relying on the front end alone for security. Hiding a field in a form or removing a button from the client doesn't stop anyone from calling the API directly with curl or Insomnia. Anyone who uses AI to generate an app's entire codebase often gets a beautiful, functional interface — but none of the invisible layers that separate a legitimate user from an attacker.

As Peter put it well in the video: "security is an architecture problem." AI just builds the mistake faster if the foundation is wrong from the start. If you ask the AI to "create a REST API for user registration," it generates exactly that — a functional CRUD, with no authentication, no role validation, no audit logs. Not out of malice: because you didn't ask for it.

Vibe coding isn't the villain — but it demands responsibility

Vibe coding is here to stay. Tools like Lovable, Bolt, v0, and Cursor let anyone with an idea put an app online in hours — and that's genuinely revolutionary. The problem isn't the tool, it's the illusion that the app is finished just because the interface looks good.

Recent data from The Hacker News (2026) revealed that more than 2,000 AI-built apps were found exposed on the open web, leaking personal and corporate data. The pattern repeats: a working API, zero authentication, sensitive files published alongside the site (.env, .git, backup.sql), missing security headers, unprotected cookies.

AI builds the mistake faster when the foundation isn't solid. That's why, before you announce your app to the world, you need a step AI won't do on its own: actually test the security. Try accessing it without logging in, force an error in the API, check what's exposed in DNS. That's the bare minimum — and hiring someone to review it is the bare minimum when your app handles user data and real money.

What ecoa.dev offers to fix this

ecoa.dev was built exactly to close that gap between "the app works" and "the app is secure." With just a few clicks, any indie developer can run a full battery of checks in minutes — not days.

The security analysis does exactly the kind of scan that would have prevented Kippu's disaster: it discovers exposed sensitive endpoints (.env, .git, admin panels, docker-compose.yml), checks security headers (HSTS, CSP, secure cookies), confirms forced HTTPS redirection, SSL/TLS, and tests for vulnerabilities like SSRF and injection. All automated, with no need for a security specialist on the team.

For apps operating in Brazil, the LGPD analysis checks whether your application complies with Brazil's General Data Protection Law: privacy policy, cookie notice with real consent, a channel for data subjects, and a named DPO. The kind of checklist no vibe-coding tool generates on its own.

And when the scan finds a flaw, ecoa doesn't just flag the problem — it generates a fix prompt ready to paste back into your favorite AI tool. You don't need to understand deep security: just copy it, paste it into Claude, ChatGPT, or Cursor, and the AI adjusts the code. It closes the hole without you having to become an OWASP expert.

On top of that, the UX analysis evaluates usability — because vibe coding tends to neglect that too — and ecoa's community of real testers provides human feedback on your app, something no AI replaces.

Security isn't a feature, it's a requirement

The Mayumi case isn't an isolated incident — it's a warning for the thousands of apps that go live every day with the rush to launch and blind trust in AI-generated code. Leaking user data isn't just a technical problem: it's a legal problem (LGPD), a financial one (refunds, fines), and a reputational one (nobody comes back after having their address exposed).

AI is here to accelerate, not to replace judgment. A beautiful platform with a wide-open API isn't a finished app — it's a walking liability. Testing security before you publish isn't a cost, it's an investment. And that's exactly what ecoa.dev exists for: helping indie devs launch with confidence, knowing their backend won't make headlines for the wrong reason.