This article was originally published on AI Study Room . For the full version with working code examples and related articles, visit the original post. Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Input Validation Deep Dive Introduction Input validation is the first line of defense against injection attacks. Every piece of data entering an application — form fields, HTTP headers, URL parameters, file uploads, API payloads — must be validated before processing. The principle is simple: never trust user input. Whitelist vs Blacklist Whitelist (Allowlist) Validation Whitelist validation defines what is allowed and rejects everything else. It is far more secure than blacklisting.…