Bubble is secure at the platform level — but your app's security is almost entirely in your hands. Because Bubble automatically exposes a Data API and sends data to the browser, a single misconfigured setting can quietly leak your users' information. Here are the seven issues I find most often in live Bubble apps, and how to close each one.
This is the number-one Bubble vulnerability, by a wide margin. If a data type has no privacy rules, its records are readable by anyone through the Data API — regardless of what your pages show. Many apps leave privacy rules at their permissive defaults and never revisit them.
The fix: For every data type, define rules so users can only see records they're entitled to. Start from "no access" and grant deliberately. Then expose only the specific fields each rule needs — not the whole record.
Anything Bubble loads into the browser can be inspected, even if it isn't displayed on screen. Hidden elements, conditionals, and "invisible" data are all still delivered to the client. Passwords hashes, internal flags, other users' details — if it reaches the page, treat it as public.
The fix: Keep sensitive fields off the client entirely. Use privacy rules to restrict which fields are visible, and move sensitive logic into backend workflows the browser can't see.
Backend workflows exposed as API endpoints can be triggered by anyone who knows the URL unless you require authentication. I regularly find endpoints that create records, send emails, or move money with no auth check at all.
The fix: Require authentication on every exposed workflow that isn't genuinely meant to be public, and validate inside the workflow that the caller is allowed to do what they're asking.
Third-party API keys placed in the client-side portion of an API connector call, or in a page's workflow, can be extracted from the browser. Once a key is exposed, anyone can run up charges or access data on your connected services.
The fix: Store keys server-side, mark them as private in the API connector, and route sensitive calls through backend workflows so the key never reaches the browser.
Hiding an admin page from the menu is not access control. If a page relies only on redirects or hidden navigation, a determined user can often reach it directly or interrupt the redirect.
The fix: Enforce access with conditions that check the current user's role on page load, and back it up with privacy rules on the underlying data so an exposed page still can't read protected records.
Trusting values that came from the browser — a price, a quantity, a user ID — lets users tamper with them before they're submitted. This is how "buy something for $0" bugs happen.
The fix: Recompute or re-verify critical values server-side in a backend workflow rather than trusting what the client sends. Never let the browser be the source of truth for anything that matters.
Every plugin you install runs in your app and can widen your attack surface. Abandoned or low-quality plugins can introduce their own vulnerabilities or leak data to third parties.
The fix: Audit your installed plugins, remove any you don't use, and prefer well-maintained ones. Review what data each plugin can access.
A structured security audit checks every one of these — and more — across your whole app, and hands you a ranked list of exactly what to fix. If you'd rather not guess, that's what I do.
The 20-point checklist behind this article, ready to run against your own app.
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