// Decision comparison
v0 vs Cursor: where generated code breaks
Quick answer
v0 and Cursor generate good code, but the risk is born in different layers. v0 is UI-first: the hole shows up in integration, in dangerouslySetInnerHTML pasted without sanitizing, in a key in a client component, in the missing CSP. Cursor generates the logic you ask for and stops at the function: the hole is access, IDOR (checks login, not owner), JWT without signature validation, skipped server validation.
So: reviewing a v0 app means looking at the seam (input, secrets, headers); reviewing Cursor code means testing ownership (does user A reach user B’s data?). Knowing the origin already directs half the review.
Different risk layers
The same goal (a secure app) requires looking at distinct points in each tool:
| Layer | v0 | Cursor |
|---|---|---|
| Dominant risk | Integration / seam | Access logic |
| Typical hole | dangerouslySetInnerHTML, key in client | IDOR/BOLA, unvalidated JWT |
| XSS | Common (unsanitized HTML) | Possible (unescaped input) |
| Authorization | Server action without owner check | Endpoint without ownership check |
| Security of the tool itself | Low (generates UI) | CVE-2026-50548 (RCE in Cursor) |
How to review each
In v0, audit the seam: every server action and where input/secrets enter, and turn on CSP. In Cursor, test ownership endpoint by endpoint and validate JWT and sessions, plus review the agent config because of the RCE CVEs. Since the Cursor hole is access logic, Risk Review (a human read) is the path; the v0 hole is often caught by the Promptbook already.
Frequently asked questions
Which generates more secure code?
Neither generates secure on its own. v0 tends to give you clean UI with integration risk; Cursor tends to give you functional logic with access holes. What matters is reviewing the right layer of each.
Does a scanner find both tools’ holes?
It finds v0’s better (XSS, headers, secrets) than Cursor’s (IDOR/BOLA), because IDOR is business logic and a scanner does not understand who the owner should be. That is why Cursor needs more human review.
Who runs the review at RET?
Gabriel Lima Ferreira, founder and lead pentester, with authorization and a tight scope.