Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale

ALTO 8.2CVE-2026-64642 · GHSA-6gpp-xcg3-4w24 · Published 27/07/2026 · updated 24/10/2026

Package	Affected versions	Patched versions
next.js vercel	`≥ 16.0.0, < 16.2.11`	`16.2.11`
next npm	`≥ 16.0.0, < 16.2.11`	`16.2.11`

Description

Impact

Crafted requests targeting Next.js applications using App Router built with Turbopack and a single entry in config.i18n.locales can bypass middleware/proxy based authentication.

Workarounds

If you cannot upgrade immediately, enforce authorization in the page's server-side data path instead of relying solely on middleware.

NVD description

Next.js is a React framework for building full-stack web applications. In versions 16.0.0 through 16.2.10, crafted requests targeting Next.js applications using App Router built with Turbopack and a single entry in config.i18n.locales can bypass middleware/proxy based authentication. This issue has been fixed in version 16.2.11.

References

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