input-validation

To validate and sanitize user input in an Express API, enforce runtime schema checks at API boundaries using libraries like Zod or Joi, and use parameterized queries to block injection attacks before data reaches databases or HTML rendering.

Securing Node.js request bodies against XSS and CSRF requires applying output sanitization and configuring CSRF middleware alongside runtime validation to ensure all external inputs are safely handled before processing.

Mapping external entry points for user data in a TypeScript codebase involves scanning source files to detect all routes, request bodies, and file uploads, identifying where external inputs reach server-side processing for missing sanitization.

Yes, schema enforcement is needed for file uploads in JavaScript server-side code because file handling represents an external input surface that requires validation and sanitization to prevent injection vulnerabilities.

Yes, you can use Zod or Joi for runtime validation at API boundaries to enforce schema checks on server-side JavaScript or TypeScript request bodies, ensuring user-supplied data matches expected formats before processing.

Unvalidated user input leads to SQL injection and data integrity issues because external data reaches databases or HTML rendering without runtime checks or parameterized queries, allowing malicious payloads to execute as injection attacks.