input-sanitization

Server-side input validation and sanitization prevent SQL injection and XSS by enforcing schema validation, parameterized queries, and HTML sanitization to strip malicious payloads before processing user data.

Server-side validation validates user registration data by checking email format, password strength, and display name length against a predefined schema using Zod before any data reaches your database.

File upload security validates file types, sizes, and content using libraries like multer and file-type to enforce content-type checks, preventing malicious files from entering your server environment.

Zod enables server-side sanitization for path traversal prevention by enforcing strict schema validation on incoming data, ensuring URL and path inputs conform to expected formats before processing.

HTML sanitization stops cross-site scripting attacks by using DOMPurify with jsdom to strip dangerous scripts and tags from user input, ensuring only safe content renders in the browser.

Client-side validation alone is insufficient for injection prevention because attackers can bypass it; server-side validation must act as the single source of truth to guard against SQL, command, and path traversal attacks.