TL;DR
Cursor is a VS Code fork with AI built in. Your code runs locally, but context is sent to AI servers for processing. The main security concerns are reviewing AI-generated code for vulnerabilities, keeping secrets out of code, and configuring .cursorignore to exclude sensitive files from AI context. Cursor itself doesn't deploy your app, so deployment security depends on your hosting choice.
How Cursor Works
Cursor is based on VS Code with AI built directly into the editor. Your code files live on your machine. When you use Chat, Composer, or autocomplete, relevant snippets get sent to Cursor's servers for AI processing. The AI then suggests code based on your prompts and what it can see in your open files.
One thing Cursor doesn't do is deploy your app. That's a separate step, and it's where most security issues actually happen.
What Code Does Cursor See?
When you use Cursor's AI features (Chat, Composer, autocomplete), the AI receives context from your codebase. This might include:
- The current file you're editing
- Files you've recently opened
- Files related to your current task
- Code you've highlighted or referenced
Privacy consideration: If you're working on proprietary code or have secrets in your codebase, be aware that context is sent to AI servers. Use .cursorignore to exclude sensitive files.
Configuring .cursorignore
Create a .cursorignore file to prevent sensitive files from being sent to AI:
# Environment files with secrets
.env
.env.local
.env.production
# Configuration with sensitive data
config/secrets.js
**/credentials.json
# Private keys
*.pem
*.key
id_rsa*
# Proprietary algorithms (if applicable)
src/proprietary/
# Large files that don't need AI context
node_modules/
dist/
*.log
Security Risks in AI-Generated Code
Cursor generates code that works. The security gaps it leaves behind are consistent enough to watch for:
1. Hardcoded Secrets
// Cursor might auto-complete with placeholder values
const stripe = require('stripe')('sk_test_example123');
const openai = new OpenAI({ apiKey: 'sk-placeholder' });
Always replace with environment variables:
const stripe = require('stripe')(process.env.STRIPE_SECRET_KEY);
const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
2. Missing Authentication
When you ask Cursor to create an API endpoint, it focuses on functionality:
// Cursor might generate this
app.delete('/api/users/:id', async (req, res) => {
await db.users.delete(req.params.id);
res.json({ success: true });
});
// You need to add authentication!
app.delete('/api/users/:id', authenticateUser, async (req, res) => {
// Also check authorization
if (req.user.id !== req.params.id && !req.user.isAdmin) {
return res.status(403).json({ error: 'Forbidden' });
}
await db.users.delete(req.params.id);
res.json({ success: true });
});
3. SQL Injection Vulnerabilities
// DON'T USE: String interpolation in SQL
const query = `SELECT * FROM users WHERE email = '${email}'`;
// USE: Parameterized queries
const query = 'SELECT * FROM users WHERE email = $1';
const result = await db.query(query, [email]);
4. Insecure Defaults
| AI Might Generate | What You Should Use |
|---|---|
| cors({ origin: '*' }) | cors({ origin: 'https://yourdomain.com' }) |
| cookie: { secure: false } | cookie: { secure: true, httpOnly: true } |
| No rate limiting | Add rate limiting middleware |
| Debug logging enabled | Disable verbose logging in production |
Secure Prompting in Cursor
Cursor's output reflects what you ask for. Ask for a login endpoint and you'll get one. Ask for a secure login endpoint with specific requirements and you'll get something better:
Include Security Requirements
// Instead of: "Create a login endpoint"
// Ask: "Create a secure login endpoint with:
// - Password hashing with bcrypt
// - Rate limiting (5 attempts per minute)
// - Input validation
// - Secure session handling
// - No sensitive data in error messages"
Ask for Security Review
// In Cursor Chat, ask:
"Review this code for security issues:
- SQL injection
- XSS vulnerabilities
- Authentication bypass
- Exposed secrets
- Missing input validation"
Cursor Security Checklist
Before Committing AI-Generated Code
No hardcoded API keys, passwords, or tokens
Database queries use parameterized statements
User input is validated and sanitized
Authentication checks on protected routes
Authorization (users can only access their data)
CORS configured for specific origins
Error messages don't leak internal details
Sensitive operations have rate limiting
Privacy Settings in Cursor
Cursor offers privacy controls you should configure:
- Privacy Mode: Prevents code from being used for training
- Codebase Indexing: Controls which files Cursor indexes for context
- .cursorignore: Excludes specific files from AI features
Enterprise users: Cursor offers additional privacy features for business accounts, including options for self-hosted models and stricter data handling.
Cursor vs Other AI Editors
| Feature | Cursor | GitHub Copilot | Windsurf |
|---|---|---|---|
| Code runs locally | Yes | Yes | Yes |
| AI context sent to cloud | Yes | Yes | Yes |
| Ignore file support | .cursorignore | .copilotignore | Settings-based |
| Privacy mode | Yes | Yes (Enterprise) | Enterprise |
| Deployment included | No | No | No |
Does Cursor store my code?
Cursor sends code context to its servers for AI processing. According to their privacy policy, code is not used for training if you enable Privacy Mode. Review their current policies for specifics on data retention.
Is code generated by Cursor secure?
Not automatically. Cursor generates functional code, but security features like authentication, input validation, and proper secrets handling often need to be added manually. Always review generated code for security issues.
Can I use Cursor for sensitive projects?
It depends on what "sensitive" means for your project. For most consumer apps and side projects, the standard setup is fine. If you're working with proprietary algorithms or regulated data (healthcare, finance), use .cursorignore aggressively, enable Privacy Mode, and look at Cursor's enterprise plan. Some organizations rule it out entirely for their most sensitive code and use offline-capable tools instead.
How do I prevent Cursor from seeing my .env file?
Add .env and other sensitive files to your .cursorignore file. This prevents them from being sent as context when using AI features. Also ensure your .gitignore includes these files.
Built with Cursor?
Scan your project for security issues in AI-generated code.