Next.js 15 Security Audit: 4 Fatal Mistakes You’re Making 🛑 #nextjs #webdev

Description

Are you building with Next.js App Router? You might be leaking database secrets and admin tokens without realizing it. In this full security audit, we break down the 4 most dangerous architectural mistakes developers make in 2026 and how to fix them using local, privacy-first tools. 🛠️ The FmtDev Offline Tool Suite Used in this Video: JWT Inspector: https://fmtdev.dev/tools/jwt-decoder CORS Config Builder: https://fmtdev.dev/tools/cors-builder Zod Schema Generator: https://fmtdev.dev/tools/json-to-zod RSC Payload Decoder: https://fmtdev.dev/tools/rsc-payload-decoder ⏱️ Chapters (Skip to your error): 0:00 - The 2026 Next.js Security Crisis 1:32 - Mistake 1: The LocalStorage Auth Trap 4:05 - Mistake 2: The CORS Wildcard Disaster 7:42 - Mistake 3: Unvalidated Server Actions 11:15 - Mistake 4: Leaking Secrets in the RSC Stream 14:10 - Why you must use "Zero Server Log" tools Read the full written Architectural Manifesto: https://fmtdev.dev/blog/the-2026-developer-manifesto #nextjs #websecurity #javascript #reactjs #cybersecurity #frontend #backend #softwareengineering #codingtutorial