Question 1

Is code generated by v0.dev secure?

Accepted Answer

Code generated by v0.dev focuses on UI components and layout, primarily producing React and Next.js code with Tailwind CSS and shadcn/ui. The generated code does not include server-side security measures like authentication, authorization, input validation, or database access controls by default. While the UI code itself is generally clean, it is designed as a starting point and assumes developers will add security layers before production use. Generated forms and inputs do not include sanitization or validation logic out of the box. UNPWNED can scan applications built with v0-generated code to identify security gaps that need to be addressed before deployment.

Question 2

Can v0.dev components have XSS vulnerabilities?

Accepted Answer

React, which v0.dev generates code for, provides built-in XSS protection by escaping values embedded in JSX by default. However, v0-generated code can still introduce XSS risks if it uses dangerouslySetInnerHTML, constructs URLs from user input without sanitization, or renders user-provided content in attributes like href or src. Components that display dynamic content from APIs or databases are particularly at risk if the data source is compromised. Server-side rendering can also introduce XSS if proper escaping is not applied during hydration. UNPWNED scans deployed applications for reflected and stored XSS vulnerabilities regardless of how the code was generated.

Question 3

Does v0.dev add server-side validation?

Accepted Answer

v0.dev primarily generates client-side UI code and does not produce server-side validation logic for form submissions or API requests. Client-side validation created by v0 can be easily bypassed by attackers using browser developer tools or direct API calls. Any form fields, input constraints, or data type checks in v0-generated components exist only for user experience and provide no security guarantee. Developers must implement server-side validation separately in their API routes or server actions. UNPWNED tests whether your application properly validates input on the server side, catching cases where client-only validation leaves endpoints exposed.

Question 4

Do v0.dev apps have CSRF protection?

Accepted Answer

v0.dev does not generate CSRF protection tokens or middleware in its output. Applications built with v0-generated code that include state-changing operations like form submissions, account updates, or payment processing are vulnerable to cross-site request forgery without additional protection. Next.js Server Actions, which v0 sometimes generates, include built-in CSRF protection when used correctly, but standalone API routes do not. Developers need to implement CSRF tokens, SameSite cookie attributes, or origin checking manually. UNPWNED checks for CSRF vulnerabilities in deployed applications and recommends specific mitigation strategies.

Question 5

Can apps built with v0.dev be hacked?

Accepted Answer

Applications built with v0-generated code can be hacked if security measures are not added beyond the generated UI components. v0 creates frontend code that handles presentation logic but does not implement authentication, authorization, rate limiting, or secure data handling. Attackers can target missing server-side validation, insecure API endpoints, broken access controls, and exposed sensitive data in client-side code. The risk is amplified when developers deploy v0-generated code directly without security review, treating it as production-ready. UNPWNED scans v0-built applications for the full range of web vulnerabilities and provides prioritized findings with fix instructions.

Question 6

How do I secure UI code generated by v0.dev?

Accepted Answer

Start by adding server-side validation for every form and input that v0 generated on the client side. Implement authentication and authorization checks on all API routes and server actions that the UI components interact with. Add Content Security Policy headers to prevent XSS attacks and set secure cookie attributes for any session management. Review generated code for any use of dangerouslySetInnerHTML, unvalidated URL construction, or direct DOM manipulation that could introduce vulnerabilities. UNPWNED provides a comprehensive scan that identifies exactly which security controls are missing from your v0-built application and guides you through implementing each one.

Question 7

Does v0.dev sanitize user inputs?

Accepted Answer

v0.dev generates form components with basic HTML input types and optional client-side constraints like required fields and pattern matching, but does not include input sanitization logic. User input rendered through React JSX is escaped by default, which prevents basic XSS in most cases. However, inputs submitted to APIs, stored in databases, or used in server-side operations are not sanitized in v0-generated code. Developers must add libraries like zod or yup for data validation and cleaning on the server. UNPWNED tests your application endpoints for injection attacks that exploit missing sanitization regardless of the frontend framework used.

Question 8

Does v0.dev generate secure authentication code?

Accepted Answer

v0.dev can generate login and signup UI components with form fields for email, password, and social login buttons, but these are purely visual components without real authentication logic. The generated code does not include password hashing, session management, JWT handling, or integration with authentication providers like NextAuth, Clerk, or Supabase Auth. Deploying v0-generated auth UI without connecting it to a proper authentication backend leaves the application completely unprotected. Developers must integrate a battle-tested auth library and properly configure secure session handling. UNPWNED scans for authentication weaknesses including missing auth on protected routes, insecure session cookies, and exposed API endpoints.

Question 9

How do I security test a v0.dev project?

Accepted Answer

Deploy your v0-built application to a staging environment and run automated security scans against the live URL to detect missing headers, exposed endpoints, and configuration issues. Test all forms and API routes for injection vulnerabilities by submitting malicious payloads through each input field. Verify that authentication and authorization are enforced on every protected route by attempting to access resources without valid credentials. Check that sensitive data like API keys and database connection strings are not exposed in client-side JavaScript bundles. UNPWNED automates all of these checks with 700+ security checks across 40 scanners and generates a prioritized report with specific fixes for your v0-built application.

Question 10

Is v0.dev code less secure than hand-written code?

Accepted Answer

v0-generated code is not inherently less secure than hand-written code at the UI component level, as it produces standard React patterns that follow established conventions. The security gap appears because v0 generates only the presentation layer without the security infrastructure that experienced developers typically build alongside it. Hand-written code by a security-aware developer would include input validation, error handling, CSP headers, and authentication checks from the start. The real risk is that v0 makes it easy to ship a polished-looking application that appears complete but lacks critical security layers. UNPWNED evaluates the actual security posture of any web application, helping teams identify gaps whether the code was generated by AI or written by hand.

v0.dev Security Questions