Security checklist for apps built with Cursor

Cursor writes code fast, and it fixes what you ask it to fix. It does not, on its own, review the whole app for security. A passive scan of the deployed site shows what the outside world can see, and the fix prompt is something Cursor can act on directly.

Common security risks in Cursor apps

1. 1. Secrets committed or bundled

   API keys pasted into code during a quick fix tend to stay there, end up in Git history and sometimes in the front-end bundle.

2. 2. Weak session cookies

   Session cookies without Secure, HttpOnly and SameSite are easier to steal or misuse. Generated auth code often leaves these at defaults.

3. 3. Missing or permissive Content-Security-Policy

   A CSP with unsafe-inline, unsafe-eval or wildcard script sources does little to stop injected scripts.

4. 4. Endpoints without authentication or rate limits

   Routes added while prototyping often stay public. Without rate limits, anything that calls a paid API can be abused.

5. 5. Debug and internal details in production

   Stack traces, debug headers, internal hostnames and HTML comments reveal more about your stack than you want.

What a FixPrompt scan checks

Passive checks on your public site, the same way a visitor's browser loads it. No attacks, no logins, no data queried.

• Secret key patterns for 30+ providers in JavaScript bundles and HTML
• Session cookie flags and lifetime
• Content-Security-Policy strength, HSTS, clickjacking and Permissions-Policy
• Common API paths that answer anonymous requests, plus rate-limit headers
• Debug headers, server banners, error pages, internal hostnames and HTML comments
• Public .git, .env, source maps and backup files

Copy-paste fix prompt

Paste this into Claude Code, Cursor, Codex or any coding agent with access to your repository. A scan gives you a prompt tailored to the issues found on your live site.

Act as a security reviewer for this codebase and fix issues in priority order:

1. Search the code and git history for hard-coded secrets. Move them to environment variables that only server code reads, and list the keys I must rotate.
2. Set session cookies with Secure, HttpOnly, SameSite=Lax (or Strict) and a reasonable lifetime.
3. Add a strict Content-Security-Policy (no unsafe-inline or unsafe-eval for scripts; use nonces if needed), plus HSTS, frame-ancestors, X-Content-Type-Options and Referrer-Policy.
4. Require authentication on every route that returns private data and add rate limiting to routes that call paid APIs.
5. Remove debug headers, verbose error pages and source maps from production.

Make small, reviewable commits and tell me how to verify each fix.

FAQ

Can Cursor fix security issues by itself?

Yes, when it knows what to fix. The FixPrompt report gives it a prioritized prompt with the evidence from your live site, so it can make targeted changes.

Does this work with Claude Code, Codex or Copilot too?

Yes. The fix prompt is plain text for any coding agent with access to your repository.

Do I need to give FixPrompt access to my code?

No. The scan only looks at the public, deployed site. Your coding agent applies the fixes in your repository.