Set server-side privacy rules correctly and enable Strict search privacy. Those two steps remove most of the data leaks I see in Bubble apps. After that, pull any Bubble API tokens out of client-side code, keep them on the server, and run the Security Dashboard to triage what's left. If those four things are done, an app has closed off the majority of its realistic attack surface, following best practices outlined in App Privacy Labels Explained.
Key Takeaways
Properly implementing server-side privacy rules and strict search privacy effectively prevents the majority of data leaks in Bubble applications.
| Point | Details |
|---|---|
| Prioritize privacy rules | Design privacy rules around ownership and roles before building the user interface to ensure proper data access control. |
| Secure file uploads | Restrict file access through server-side permissions, validate file types and sizes, and avoid exposing upload tokens publicly. |
| Review API and plugins | Audit third-party plugins, API permissions, and rate limits regularly to minimize external and internal security risks. |
| Conduct targeted security audits | Start with critical areas like privacy rules and API tokens, then address findings systematically for better security assurance. |
| Follow Hanad Kubat’s approach | We recommend using privacy rules as the core authorization model, rotating exposed tokens immediately, and conducting regular security reviews. |
Table of Contents
- Common vulnerabilities in Bubble that cause data exposure
- Authentication, authorization, and access control: what to configure and test
- How to secure file uploads and prevent leaked files
- Plugins, backend workflows, API settings, and rate-limiting risks
- A prioritized, runnable Bubble security audit checklist
- My practical recommendations: platform assurances vs. application responsibility
- Common mistakes and a realistic path for founders
- A fixed-price way to get a clear answer on your Bubble app
- FAQ
- Sources
Common vulnerabilities in Bubble that cause data exposure
Most Bubble data leaks trace back to one mistake: treating the interface as the security boundary instead of the database. A page can hide a field from view, but if the underlying privacy rule allows it, the data still travels to the browser and anyone with basic developer tools can read it. Privacy rules are the actual authorization layer, and data that fails a rule never reaches the client in the first place.
A second, less obvious pattern is search inference. Even when a field itself is hidden, an app can leak its contents if that field is allowed as a search constraint. Someone can run searches that narrow results until they effectively reconstruct private data, one guess at a time. This is exactly why Strict search privacy matters: it requires explicit permission before any field can be used as a constraint, closing off that inference path.
One audit stat worth remembering: Bubble's own Security Dashboard issue catalogue lists missing privacy rules, exposed file uploaders, credentials sitting in workflows or URLs, unsafe API configuration, and unprotected backend workflows as the recurring categories it flags, which lines up with what shows up in real audits.
When I review an app, I check these first:
- Data types where "view all fields" is checked for a role that shouldn't have it.
- File uploaders with no privacy rule restricting who can view the uploaded file.
- Editor or collaborator accounts with more access than their role requires.
- Environment variables or API keys pasted directly into a workflow or exposed in a page URL.
- Pages and reusable elements that display sensitive fields without a matching server-side rule.
Fixing this is rarely complicated. The harder part is finding them, because a Bubble app can look correct in the editor while still leaking data through a search box or an API call nobody remembers configuring.
Authentication, authorization, and access control: what to configure and test
Privacy rules should be designed around ownership and role first, with the interface built on top of that, not the other way around. One detail that trips up a lot of builders: Bubble privacy rules are additive. If two rules could both apply to a user, the result is the union of what each one grants, not the more restrictive of the two. A broad convenience rule added for one feature can quietly grant access everywhere else.
A practical sequence for locking this down:
- Write narrow, ownership-based rules first (a user sees only records where they are the creator or an assigned member), then add exceptions deliberately.
- Enable MFA for admin and staff accounts, and apply a reasonable password policy for any account that can reach sensitive data.
- Set Search privacy mode to Strict for any app holding private data, then go through each data type and confirm which fields are allowed as search constraints.
- Restrict who has editor access to the app and review what each collaborator can actually change, especially on the Live branch.
- Keep Bubble API tokens out of client-side code entirely. A token used client-side can be read by anyone who opens the browser console, and a request authenticated with that token gets full admin access that bypasses privacy rules.
Pro Tip: Treat any privileged token exposure as a live incident: rotate the token immediately rather than waiting to see if it was actually used.
Session handling deserves the same scrutiny as login. If an app allows long-lived sessions with no re-authentication for sensitive actions, that session becomes a standing risk once a device is lost or shared. For apps handling regulated data, pairing role-based rules with role-based access control patterns from outside the Bubble ecosystem can clarify what each role should actually be allowed to do before you translate it into privacy rules.
How to secure file uploads and prevent leaked files
Files behave differently from regular data fields, and that catches people off guard. Once a file is downloaded to a browser, it's readable. There's no way to redact it after the fact, so the only real control is whether the download happens at all, and that depends entirely on the privacy rule attached to the file field.
The fixes that matter most:
- Disable "view" on sensitive file fields by default, and route access through a server-side workflow that checks permission before returning the file.
- Validate file type and size on the server, not just in the uploader's client-side settings, since those settings can be bypassed.
- Keep any upload token or endpoint out of client-visible code, and require authentication before a workflow accepts a file.
- If uploads carry real risk (identity documents, financial records), consider scanning or proxying them rather than serving them directly.
- If the app uses external object storage with signed URLs, check how long those URLs stay valid. A signed URL that never expires is a permanent leak waiting to happen.
Pro Tip: Ask a colleague to try opening a file URL directly, without logging in, from a browser's private window. If it loads, the privacy rule isn't doing its job.
Plugins, backend workflows, API settings, and rate-limiting risks
Plugins and third-party integrations deserve the same scrutiny as code you write yourself, because that's effectively what they are. Before trusting one, check what permissions it requests, how recently it was updated, and whether its actions are visible in your workflow logs.
Backend workflows carry their own quiet risk. Any workflow set to "ignore privacy rules" is operating with elevated privilege by design, which makes sense for some admin operations but means that workflow needs its own validation, logging, and restricted access, the same way you'd treat a privileged backend endpoint in any other stack.
A few other items worth a direct check:
- Data API permissions for Create, Modify, and Delete are disabled by default and should stay that way unless a specific integration genuinely needs them.
- Public-facing endpoints that accept form submissions or search queries benefit from rate limiting or a captcha to blunt brute-force and scraping attempts.
- Internal API documentation (anything like a Swagger-style explorer) should not be publicly discoverable, since it maps out your attack surface for free.
None of this requires exotic tooling. It requires going through each surface once, on purpose, instead of assuming the platform handles it.
A prioritized, runnable Bubble security audit checklist
A useful audit doesn't try to review everything at once. It starts with what could expose the most data fastest, then works outward.
- Take a pre-audit snapshot: export the collaborator list, current app settings, Data API status, and Search privacy mode so you have a baseline to compare against later.
- Go through every data type's privacy rules: confirm "view all fields" isn't granted to roles that don't need it, and check which fields are marked as valid search constraints.
- Triage Security Dashboard findings in order of severity: missing privacy rules and exposed file uploaders first, compromised or unused tokens next.
- Inventory every API token the app has issued, rotate anything that's been exposed, and move admin-level operations into server-side workflows.
- Inspect workflows for "ignore privacy rules" and add caller validation plus an audit log for each one you find.
- Test abuse cases directly: attempt search inference on a hidden field, call the Data API unauthenticated, and try downloading a file without logging in.
- After the fix pass, schedule a recurring check, fold the checklist into your deployment routine, and write down any exception you intentionally allowed and why.
| Audit area | What to check | Priority |
|---|---|---|
| Privacy rules | View, search, and modify permissions per data type | High |
| Search privacy mode | Strict vs. Automatic vs. Off | High |
| API tokens | Location in code, rotation history | High |
| File uploaders | View permission, server-side retrieval | High |
| Backend workflows | Use of "ignore privacy rules" | Medium |
| Plugins | Permissions requested, update frequency | Medium |
| Rate limiting | Public endpoints, login forms | Medium |
A checklist like this takes a few hours to run properly on a small app and considerably longer on one with years of accumulated workflows. Either way, it's the difference between guessing an app is secure and knowing which specific rules protect which specific data.
My practical recommendations: platform assurances vs. application responsibility
Bubble as a platform does real work on infrastructure security. Its enterprise security documentation describes annual penetration testing and SOC 2 Type II compliance, which covers the platform layer. None of that enforces privacy rules inside your specific app. That part is entirely on you.
I treat privacy rules as the canonical authorization model for any Bubble app I touch: design the rules first, build the interface second, never the reverse. Privileged actions belong in server-side workflows, and any token that might have been exposed gets rotated immediately, not eventually.
Platform-level testing reduces infrastructure risk. It does not substitute for an app owner designing correct privacy rules.
When an app handles regulated or high-value user data and keeps hitting the edges of what Bubble's rule system can cleanly express, a focused rebuild into real code is often the more defensible long-term path.
Common mistakes and a realistic path for founders
The mistakes repeat: trusting a client-side check that a server never verifies, leaving search constraints wide open, and letting an API token sit in a workflow someone forgot about. None of these are exotic. They're the result of moving fast and not revisiting settings once the app works.
For an owner-operated app, start with privacy rules and a token inventory. Those two alone close most of the real risk. If you want certainty rather than a best guess, a focused audit followed by a rebuild is a reasonable investment once the app handles anything sensitive.
— Hanad Kubat
A fixed-price way to get a clear answer on your Bubble app
If you'd rather have someone go through this systematically than do it alone, I run a fixed-price Prototype Audit: three to five days, a prioritized list of what's actually exposed, and a clear recommendation on whether targeted fixes are enough or whether the app has outgrown what Bubble's rule system can safely express. The audit fee is credited against a build if you move forward. From there, builds start at €12,000, priced without agency overhead or a project-manager layer in between, because it's one senior engineer doing the work you'd otherwise pay a team for. You can see current scope and book a slot on my services page.
FAQ
What is the Kpop Bubble app and how does it work?
That Bubble app is a separate fan-messaging product unrelated to the Bubble.io no-code platform discussed in this article. It lets fans receive messages from artists and isn't built on Bubble.io, so the security practices here don't apply to it.
Is Bubble.io real?
Yes, Bubble.io is an active, established no-code platform used to build and host web applications, with its own documented privacy rules and security tooling. It's a real product with real infrastructure, not a placeholder or a test service.
Is the JYP Bubble app legit?
That app is a legitimate, separate fan-communication product unrelated to the Bubble.io platform covered in this article. Questions about its legitimacy should go to its own publisher rather than to Bubble.io's documentation.
What is the Bubble app used for?
Bubble.io is a no-code platform people use to build web applications, from internal tools to customer-facing SaaS products, without writing traditional code. Because it manages its own database and server logic, privacy rules are the mechanism that decides which users can see which data.
How often should I audit a Bubble app's security?
A reasonable baseline is after any major feature release and at least twice a year for an app handling private user data. The Security Dashboard is built to be rechecked on a schedule, not just once at launch.