The plain-English version
Checking incoming values in the trusted processing environment before applying an operation.
Why it matters
Browser checks improve usability but cannot establish what a modified or direct request may submit.
Let’s make it click
The server rejects a title that exceeds the supported length and returns field-level feedback.
Vibe Bro’s heads-up
A valid value can still be unauthorized; input validation does not replace ownership or permission checks.
The docs behind it
Documentation links checked .
Editorial review · October 28, 2026
Supported: OWASP requires validation at server trust boundaries because clients can bypass browser checks. Validation is correctly distinguished from authorization.