An app built primarily with Cursor carries the security posture of whatever code got accepted during AI-assisted edits. Cursor is very good at making code that runs, and has no default mechanism for flagging a hardcoded key, a missing header, or an overly permissive database rule, unless you explicitly prompt it to review for those things.
Why this happens in Cursor-built apps
Cursor accelerates writing and editing code across an entire codebase, which means it can introduce or fail to catch a security gap anywhere in that codebase, not just in newly generated files, but in edits to existing configuration, deploy scripts, or backend rules.
A pair-programming tool optimizes for the request in front of it. "Make this feature work" and "review this for security" are different prompts, and only one of them gets asked by default during most sessions.
Common issues in Cursor-built apps
What shows up across Cursor-assisted codebases:
- Hardcoded keys accepted during a quick edit: it's easy to accept a suggested edit that hardcodes a key "to get past this error," intending to move it to an environment variable later, and just as easy for that intention to never happen before deploy.
- No systematic header or CORS review: Cursor edits the code you point it at; it doesn't proactively audit your deployed headers, CORS policy, or cookie flags unless you ask it to, and most sessions are focused on features, not a security pass.
- Backend rules drifting from what the code assumes: as a codebase built with AI-assisted edits grows, it's common for the actual database or API access rules to drift from what the application code assumes is enforced, a gap only a check against the live, deployed target will catch.
How to fix it
Treat a security pass as a distinct, deliberate prompt/session:
- Explicitly ask Cursor to grep the codebase for hardcoded secrets before a deploy, rather than assuming an earlier "I'll fix it later" got resolved.
- Run a dedicated pass over deployed headers, CORS policy, and cookie flags. Cursor can help write the fix, but the check has to be requested.
- Verify database/API access rules against the live target rather than the source code, since the two can silently drift apart as the codebase grows.
Frequently asked
Can I just ask Cursor to "review this for security"?
You can, and it helps. Cursor can flag obvious patterns like a hardcoded key or missing header check when explicitly asked. What it can't do is check your live, deployed target's actual configuration, since that's outside the codebase it's editing.
Is a codebase with more AI-assisted edits automatically less secure?
Not automatically. The risk is that nothing enforces a security review by default, not that AI-written code is inherently worse. A codebase with zero AI assistance and zero security review has the same gap.