Key takeaways
- A Lovable app talks to its Supabase database straight from the browser with a public key, so row-level security (RLS) is what stops one user from reading everyone's data.
- Lovable's own docs say "Missing RLS policies are the most common way app data gets exposed," and that its scans "cannot guarantee complete security."
- The Quick scan runs every time you publish, but the Deep scan, which reviews your app code, does not run automatically.
- Reverting in Lovable restores your code, not your database data, so test risky changes before real users depend on them.
- Supabase now requires an explicit grant for new tables (in all existing projects from October 30, 2026), and existing tables keep theirs, so old leaks stay open.
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Problems with real Lovable apps often show up in the same few places: database access rules, keys in the browser, server functions that don’t check the caller, and the gap between the preview and the live app. A Lovable app is a web app that talks to a Supabase database, either Lovable’s built-in backend (called Cloud in the docs, which Lovable says uses “Supabase’s open-source foundation”) or a Supabase project you connect. The browser calls the database directly with a public key, so the database rules are what keep one user’s data away from another.
Below are the seven problems to check before launch, how to test each one in a few minutes, and how to fix it. The facts below come from Lovable’s and Supabase’s own documentation and from the public security report on Lovable apps, and I re-read each source on October 22, 2026. The how-to-check and how-to-fix steps are my own advice.
1. Tables anyone can read or change
Lovable’s Supabase guide is blunt: “Missing RLS policies are the most common way app data gets exposed.” A table in the public schema with row-level security (RLS) turned off, or with a policy like USING (true), can be read, and often changed, by anyone who has your app’s public key. That key ships in your site’s JavaScript by design.
This is not a hypothetical. CVE-2025-48757 describes “an insufficient database Row-Level Security policy in Lovable through 2025-04-15” that, per the CVE text, allows unauthenticated attackers to read or write tables of generated sites. The entry is marked as disputed by Lovable, because each customer is responsible for protecting their own app’s data. The researchers who filed it report that their own March 2025 scan found 303 endpoints across 170 projects, about 10.3% of the 1,645 they analyzed, with inadequate RLS settings.
How to check: open Supabase’s Security Advisor and look for “RLS disabled in public” and “policy exists, RLS disabled”. To review the policies themselves, paste your policy SQL into the free Supabase RLS policy checker, which flags policies of true, sign-in-only checks and open storage buckets. Then request each table with only the public key and no login. The free scan at the end of this page does that for you.
How to fix: turn on RLS for every table in the public schema and write policies that tie rows to auth.uid(). Remove any policy that lets everyone in. Already turned RLS on? See why data can still be exposed with RLS on.
2. A green scan with the wrong policies
Lovable’s Quick scan “runs automatically every time you publish” and checks things like tables without RLS. A table can have a policy and still let the wrong people in. The CVE researchers said in 2025 that the scanner they tested only checked that a policy existed, “not its correctness”. Lovable’s current Quick scan reviews database access rules, for example tables without per-record access control, but it is still a fixed set of checks. Lovable itself says its tools “cannot guarantee complete security”.
How to check: Lovable’s security best practices guide says to check before going live that “Users cannot access other users’ private data.” Test that with a second account on every screen that shows private data, and repeat it for each role your app has.
How to fix: rewrite any policy that fails the two-user test, then test reads, inserts, updates and deletes separately. A policy that blocks reads can still allow writes.
3. Secret keys in the browser
Lovable’s security docs explain that it “generates frontend code that runs in the browser, which means API keys and other secrets cannot be stored safely in client-side code.” Supabase says the same about its secret and service_role keys: never put one in a browser, a shipped app or source control. Stripe secret keys, AI provider keys and admin keys belong in the same category.
How to check: search your GitHub repository and the built JavaScript for service_role, sb_secret_, sk_live and your providers’ key prefixes.
How to fix: rotate any secret that was ever exposed, then move the call into a server function that reads the key from Lovable’s Secrets. Only the publishable or anon key belongs in the browser (is the anon key in my code a problem?).
4. Server functions that don’t check who is calling
Payments, emails, AI calls and admin actions usually run in Supabase Edge Functions that Lovable writes for you. A function that uses the service key skips RLS entirely, so it has to check the caller itself. Supabase’s default is verify_jwt = true, so “the platform validates the JWT before your handler runs”, and it warns against turning that off just to clear an error.
How to check: call each function with no token, then with a normal user’s token for an action only an admin should take. Look for verify_jwt = false in supabase/config.toml. Lovable’s Deep scan reviews this kind of access control in your code, but “the Deep scan does not run automatically”, so run it yourself.
How to fix: keep JWT verification on for anything a user triggers, check the user’s role and ownership inside the function, and verify webhook signatures for calls from Stripe or other services.
If one of those functions comes back as 504 Gateway Timeout or 546, the Edge Function timeout fix shows which limit it hit and how to move the slow part into a background task.
5. Views and storage that skip your rules
Locking down a table is not enough if a view or a storage bucket exposes the same data. Supabase’s advisor warns that a security definer view “runs with elevated privileges and ignores Row-Level Security”. Files in a public storage bucket can be opened by anyone with the link.
How to check: in the Security Advisor, look for “security definer view” and “auth users exposed”. In Storage, list which buckets are public.
How to fix: recreate views with security_invoker = on, copy the user fields you need into a profiles table instead of exposing auth.users, and make buckets with private files private, with storage policies.
6. The Supabase October 30, 2026 change
Supabase’s changelog says that from May 30, 2026 new projects stop exposing new tables to the Data API by default (a gradual rollout over a few weeks), and that on October 30, 2026 the setting is applied to all existing projects. Once it applies to your project, a new table in the public schema fails with “permission denied for table” until a migration grants it. Supabase also says “existing tables are not affected”, so a table that is open today stays open.
If your Lovable app uses a Supabase project you own, the change applies. Lovable’s docs don’t say whether Lovable Cloud follows the same default or adds grants to the migrations it writes, so after October 30, create a test table and check it from the app.
How to check: paste your migrations into the free Supabase October 30 grants checker. The full guide to the change has the exact grant lines.
How to fix: add a grant per role in the same migration that creates each table, next to RLS and its policies.
7. No safe path between the preview and production
Three facts from Lovable’s docs catch teams out once real users arrive:
- Reverting doesn’t undo data changes. Lovable’s version history docs say reverting restores “your project’s code only” and “does not restore or roll back your database data”. A bad migration or a test that wrote to the live database stays in the database.
- The live site is a snapshot. It only changes when you publish again, so the preview and the live app can drift apart. If the published site is a blank page, see Lovable app blank after publishing.
- GitHub sync has limits. “Lovable only edits and syncs one branch at a time”, and “Git sync always creates a new repository”, so you can’t attach a project to an existing repository. Two people, or Lovable and a local editor, pushing to the same branch can overwrite each other’s work. If sync has stopped, see Lovable GitHub sync not working. For the other errors Lovable, Bolt and Replit apps hit, see the AI app builder errors guide.
Moving off Lovable Cloud is possible but manual, and removing the built-in backend “permanently deletes the database, its backups, your app’s user accounts, and the files in storage, and cannot be undone”, so export your database and files first. The Lovable Cloud to Supabase move goes through it in order.
How to fix: export and test a database backup before launch, keep schema changes in migrations in the repository, agree who pushes to the synced branch, and run payments in test mode until the two-user test passes.
What to do this week
- Run the free leak scan below against your live site.
- Do the two-user test on every page with private data.
- Search your repository for secret keys and rotate anything you find.
- Run Lovable’s Deep scan and read every finding.
- Check your newest migrations for grants with the free Supabase grants checker.
Stuck on one error and prompting “fix it” again? The Lovable and Bolt credits calculator turns the Lovable credits you have already spent on it into dollars at your plan’s rate.
After the fixes: can Google and AI assistants read it?
Check one thing before you announce it: open your live page, view the page source (not the inspector), and search for a sentence from your page. If it isn’t there, the text only appears after JavaScript runs. Google renders JavaScript, but Vercel’s December 2024 crawler study found that OpenAI’s, Anthropic’s and Perplexity’s crawlers (GPTBot, OAI-SearchBot, ChatGPT-User, ClaudeBot and PerplexityBot) don’t, so a page that builds its text in the browser gives those crawlers nothing to read, and an assistant that relies on them can’t quote it. Lovable’s FAQ says apps created from May 13, 2026 render pages on the server, while older apps render in the browser and get pre-rendered copies served to search engines and AI crawlers. If search matters for this app, the SEO, GEO and AEO page explains what makes a site readable for Google and AI assistants, and the $750 AI Search Visibility Audit checks it for you.
Need a hand?
For a free first look, enter your live app’s address in the AI app security check. It flags secret keys shipped in your JavaScript and missing security headers in a few seconds, without logging in or touching your database.
If you’d rather have someone else check it, the AI-Built App Rescue starts with a $450 Launch Check. You send read-only access, and within 3 business days you get each problem ranked by severity, with where it is and how it was confirmed, plus a fixed price for the Rescue Sprint. The $450 is credited if you go ahead, and you keep the code either way. Built with something else? See the Bolt, Replit, Cursor, Base44 and v0 checklists. Or send me a short description.
On Supabase? The Supabase security review before launch covers every Supabase setting to check, with an order for fixing them. Comparing who should do the work? Hiring someone to finish a vibe-coded app compares freelancers, agencies, builder partners and fixed-price checks, with 10 questions to ask before you hire. Ready to hire for your Lovable app? Hire a Lovable developer sets out when you need one and what it costs.
Is your app leaking data?
Scan your live Supabase project for tables anyone can read with the public key your site already ships. Built for Lovable, Bolt and hand-built apps. The scan only asks whether each table has rows a logged-out visitor can see. It never fetches, stores or shows a row.
Want this done at a fixed price?
Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.
Frequently asked questions
- Is my Lovable app secure if the security scan passes?
- Not necessarily. Lovable says its scans "cannot guarantee complete security", and the Quick scan that runs on publish does not review your app code. Run the Deep scan and test access yourself with two accounts and with no login.
- Why can other users see each other's data in my Lovable app?
- Usually because a table has row-level security turned off, or a policy that lets everyone in, such as USING (true). The browser talks to the database with a public key, so the policies are the only thing deciding who sees which rows.
- Does the Supabase October 30, 2026 change break my Lovable app?
- Existing tables keep working. Once the change applies to your project (new projects from May 30, 2026 in a gradual rollout, all existing projects on October 30, 2026), new tables return "permission denied" until a migration grants them to the right roles. If your app uses a Supabase project you own, the change applies. Lovable's docs don't say how Lovable Cloud handles it, so test a new table after that date.
- Can I move my Lovable app off Lovable Cloud?
- Yes, but it is manual. You export your data and files, connect your own Supabase project and rebuild the schema. Lovable says removing the built-in backend "permanently deletes the database, its backups, your app's user accounts, and the files in storage, and cannot be undone", so export first.
- Do I keep my code if I hire someone to fix my Lovable app?
- Yes. Lovable syncs your project to a GitHub repository you own, and a developer can work from that repository. Lovable only syncs one branch at a time, so agree on which branch Lovable edits before anyone else pushes to it.
Sources
- Lovable docs, Security
- Lovable docs, Supabase integration
- Lovable docs, Lovable Cloud
- Lovable docs, GitHub integration
- Lovable docs, Prompting best practices
- NVD, CVE-2025-48757
- Matt Palmer, Statement on CVE-2025-48757
- Supabase changelog, tables not exposed to the Data API automatically
- Supabase docs, Database advisors
- Supabase docs, API keys
- Supabase docs, Edge Functions auth
- Lovable docs, Built-in backend (Cloud)
- Lovable docs, Version history and revert
- Lovable docs, Security best practices
- Lovable docs, Hosting
- Lovable docs, FAQ
- Vercel, The rise of the AI crawler
- Supabase docs, Database linter, security definer view
Related Resources
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