Bubble Security Guide: Privacy Rules, API Tokens, and Data Exposure

Quick answer: Review Bubble Privacy Rules, Data API exposure, API Connector secrets, and backend workflow authorization. Test access with separate users and no session. SimplyScan adds bounded checks of public responses; a scan cannot establish that every private workflow is protected.

By Daniel A · Kraftwire Software

Review Bubble Privacy Rules, Data API settings, API Connector secrets, and backend workflow authorization. Test which records and operations are accessible to unauthenticated callers and other users. Bubble’s controls need to match the application’s intended access policy.

A visible login page does not establish that every data access path requires a session. Inspect the effective permissions directly.

These live figures describe all scanned sites. They do not establish prevalence for an AI-built subgroup, compare development methods, or attribute findings to AI generation.

30% of the 119 live sites SimplyScan has scanned (36 sites) have at least one high or critical security issue.

Whether a feature works in the interface is separate from whether its server-side access controls are correct.

The Critical Bubble Security Checklist

Use this checklist to organize configuration review and application-specific testing. A feature that works in the interface still needs authorization tests.

1. Missing Privacy Rules: Review Data Access

Bubble Privacy Rules control access to data and fields. Review them together with Data API exposure and request credentials. They serve a similar purpose to row-level access policies, but are not PostgreSQL RLS.

Hiding a field in the interface does not remove data already sent to the browser. Inspect the response as well as the page, including the version-test environment if it is accessible.

• Data API: Access depends on exposed data types, applicable Privacy Rules, and the caller’s credentials. An administrative API token bypasses Privacy Rules.
• Owner Conditions: A condition such as This [Data Type]'s User is Current User can restrict access when its associated permissions are configured correctly. Review all matching rules and the “Everyone else” permissions, then test expected allow and deny cases.

For a deeper look at how this works in other ecosystems, see our RLS policies explained guide.

2. Exposed API Tokens and Admin Access

API tokens authenticate API requests within the permissions assigned to the credential. Distinguish administrative credentials from user-scoped tokens.

Keep administrative API credentials server-side. Revoke exposed tokens and investigate the records and operations they could access.

• API Connector: Mark secret parameters private and avoid secrets in initialization defaults or client-visible expressions.
• Revocation: Verify that the old credential is disabled and update authorized integrations. Revocation does not undo previous access.

3. Unprotected Backend Workflows

Backend workflows can perform sensitive operations such as payment processing, role changes, or data updates. Their authorization must cover the operation and the records affected.

• Authentication: Review which exposed workflows accept unauthenticated calls. A public endpoint needs an intentional access policy and abuse controls.
• Webhooks: Verify the provider’s documented authentication or signature mechanism before performing sensitive actions; an arbitrary secret parameter is not a universal substitute.
• Audit Step: Test authorized and unauthorized calls in an isolated environment. SimplyScan’s workflow inventory observes responses without executing the workflow; it cannot establish whether an unauthenticated invocation would succeed. See the application security checklist.

4. Data Exposure via Search and URL Parameters

Inspect which fields a search response sends to the browser and how access is checked when a URL identifies a different record.

• Search Constraints vs. Privacy Rules: Interface filters do not establish authorization. Configure server-enforced permissions and inspect returned fields.
• Record IDs: Treat IDs as references, not secrets. Test whether another user can read a record when given its ID.
• Option Sets: Do not store secret keys or private data in client-visible Option Sets.

5. Windsurf and Cursor Security Risks in No-Code

When using AI agents like Windsurf or Cursor to write custom code or plugins for Bubble, you introduce a new layer of risk. Review generated code and deployment configuration independently of whether the visible features work.

• AI-Generated Vulnerabilities: AI may suggest insecure patterns, such as passing sensitive data through URL parameters or failing to sanitize inputs in a custom JavaScript action. This can lead to XSS or code injection.
• Code Review: Always perform an ai code review security check on any custom code snippet. Do not assume the AI understands the security context of your Bubble app.
• Tooling: For those using these agents, refer to our Windsurf security guide and Cursor security checklist as part of reviewing your AI-assisted development workflow.

6. Securing the Test Environment

Restrict access to test environments and avoid copying sensitive production data into them.

• Access Controls: Restrict the test environment using the platform’s supported controls and verify access from an unauthenticated browser.
• Data Hygiene: Prefer synthetic test records. Avoid copying private production data into development environments.
• Monitoring: Uptime monitoring reports availability observations. It does not prevent outages or establish that access controls work.

Performance and Security: The Hidden Link

Security isn't just about data leaks; it's about availability and reliability.

79% of the 119 live sites SimplyScan has scanned (94 sites) have at least one medium-severity speed issue, such as render-blocking scripts or no route-based code splitting.

Investigate slow responses as performance findings. They do not by themselves establish susceptibility to denial of service.

• Resource Use: Review expensive searches, workflow execution, and abuse limits under an authorized load-testing plan.
• Availability: Investigate downtime and response changes using monitoring and application logs.
• Compliance Signals: SimplyScan checks observable privacy-policy and consent signals. It does not determine legal compliance.

25% of the 119 live sites SimplyScan has scanned (30 sites) have at least one high-severity compliance issue, such as no linked privacy policy.

How to Audit Your Bubble App with SimplyScan

Use SimplyScan’s Bubble scan for supported public-response checks alongside manual testing.

Run a Free Scan

Enter your URL at simplyscan.io. The scan takes ~30 seconds and requires no signup.

Check the 8 Dimensions

We grade security, speed, SEO, AI visibility (AEO), accessibility (WCAG), GDPR signals, domain health, and email security (SPF/DKIM/DMARC).

Identify Exposed Data

The engine checks supported anonymous Data API responses for sensitive-data signals, inspects security headers, and looks for a publicly rendered version-test page. A readable test page alone does not prove a data leak.

Investigate Findings

Review the findings and their coverage. Test private workflows and cross-user access separately; a URL scan does not verify every Bubble configuration.

Advanced Protection: Security Headers and Compliance

For apps handling sensitive data, standard Bubble settings are just the baseline.

• Security Headers: Configure and test a Content Security Policy suited to the application. It can limit some XSS effects, but does not replace safe output handling. See the CSP guide.
• Email Security: SPF, DKIM, and DMARC support sender authorization, message signatures, and domain policy. They reduce some spoofing risks but do not prevent all fraudulent mail.
• AEO: Review crawler access and content separately from security; access does not guarantee indexing or citation.

Summary of Key Takeaways

• Privacy Rules: Test effective record and field access for each user class.
• API Tokens: Keep administrative credentials server-side and revoke leaks.
• Backend Workflows: Enforce the intended authentication and authorization before sensitive actions.
• Test Environments: Review access to the version-test site and its data.
• Scanning: SimplyScan grades 8 dimensions, including security and speed, using its supported checks. Follow up on coverage gaps.

Deep Dive: The Anatomy of a Bubble Data Breach

Consider a data type named Customer_Invoices exposed through the Data API at https://your-app.bubbleapps.io/api/1.1/obj/customer_invoices. The endpoint’s effective access depends on the app settings, Privacy Rules, and request credentials.

If anonymous access permits finding records and reading private fields, an unauthenticated response can reveal invoice information. Inspect pagination and field permissions; a single response need not contain every record.

Protecting the API Connector

For a secret header such as Authorization: Bearer [YOUR_SECRET_KEY], review the API Connector’s “Private” setting and initialization values.

Bubble documents that private parameters are kept out of client code and added server-side to outbound requests. Do not assume every non-private parameter changes the call into a direct browser request. Inspect the deployed client code and network responses for unintended disclosure.

Architecture Risks in AI-Built Apps

When generated code or external integrations interact with Bubble data, inspect the permissions at each boundary. The builder’s name does not establish the resulting architecture’s safety.

11% of the 119 live sites SimplyScan has scanned (13 sites) have at least one medium-severity architecture issue, such as a library with a known vulnerability or no rate limiting.

Investigate individual findings and their check definitions before attributing a cause or interpreting the aggregate category.

Specify intended access rules during development, then test the resulting configuration. A prompt asking for secure architecture is not evidence that the access rules were implemented correctly.

Related Guides

• The Ultimate Vibe Coding Security Checklist
• Is Bubble Safe? A Deep Dive
• No-Code Platform Security Guide
• Xano Security Guide
• FlutterFlow Security Guide
• Weweb Security Guide
• Firebase Rules for AI Apps
• CSRF and Security Headers Guide

FAQ

Is Bubble secure by default?

Assess the deployed configuration rather than assuming a universal secure or insecure default. Review exposed data types, Privacy Rules, request credentials, and workflow authorization. Test both permitted and denied access.

What are privacy rules in Bubble and do I really need them?

Privacy Rules govern access to Bubble data and fields. Configure them for non-public information, review every applicable rule, and test searches and record access with separate users. Administrative API tokens bypass these rules.

What can an attacker do with a leaked Bubble API token?

A leaked administrative Bubble API token can bypass Privacy Rules for API access. Revoke it, update authorized integrations, and investigate the records and operations it could access. Do not treat a user-scoped token as equivalent to an administrative token.

Which security checks are available for Bubble?

Review the controls and plan requirements shown in Bubble’s current documentation. SimplyScan offers a free URL scan of publicly observable signals, but it does not inspect all editor settings or execute private workflows.

Review scan observations together with the application’s configuration and authenticated test results.

How do I find out if my Bubble app is leaking data?

Inspect network responses as an unauthenticated visitor and as separate test users, then compare the results with the intended policy. SimplyScan adds bounded anonymous Data API, security-header, and test-page checks; it does not replace authenticated testing.

Is a secret URL enough to protect a Bubble backend workflow?

An unlisted URL does not establish authorization. Enforce the workflow’s intended access policy and validate the caller before sensitive actions. For webhooks, verify the provider’s documented authentication or signature mechanism.