Define the security question
A Next.js security checklist for App Router teams that need server actions, middleware, route handlers, and previews reviewed as real entry points.
Harden Next.js App Router apps with checks for Server Actions, route handlers, middleware, previews, cookies, and headers.
Page intent
resourceA Next.js security checklist for App Router teams that need server actions, middleware, route handlers, and previews reviewed as real entry points.
This resource is structured as an operating guide: use it to scope the work, make decisions explicit, and turn the result into something engineering, leadership, or buyers can review.
A Next.js security checklist for App Router teams that need server actions, middleware, route handlers, and previews reviewed as real entry points.
Inventory App Router pages, route handlers, Server Actions, middleware, and preview deployments.
Test authorization and validation on server-side functions, not only components.
Next.js route inventory
Generate a route and server-entry inventory.
Mark which entries require auth, role checks, tenant checks, or input validation.
Test high-risk entries with invalid roles, IDs, payloads, and sessions.
Attach retest notes to the release or pull request.
Next.js route inventory
Server Action authorization matrix
middleware coverage notes
preview deployment decision log
Server Actions accepting unauthorized or unvalidated input.
Route handlers exposing data outside intended UI flows.
Next.js route inventory
Middleware missing localized, dynamic, or API routes.
Server Actions accepting unauthorized or unvalidated input.
Route handlers exposing data outside intended UI flows.
Middleware missing localized, dynamic, or API routes.
Public environment variables leaking assumptions or sensitive endpoints.
They can mutate server-side state and should be treated like public endpoints with authorization and validation requirements.
Teams often protect visible pages but miss API routes, localized paths, dynamic segments, or preview-specific behavior.
Yes, especially when previews contain seeded data, unfinished admin flows, or public URLs.
SafeVibe maps routes and server entries to checks, owners, fixes, and retest evidence.
Use Next.js security checklist as the starting point, then turn the checklist into SafeVibe scan scope and remediation evidence.