Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale (CVE-2026-64642)
## 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.
Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale (CVE-2026-64642)
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.
CVSS v4.0
Affected software
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Weaknesses
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-6gpp-xcg3-4w24
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-64642"]
- Ecosystems
- ["npm"]
- Database Specific Severity
- HIGH
- Cvss Version
- 4.0
Threat ID: 6a616bcd9c2644c7f80dbdb9
Added to database: 07/23/2026, 01:18:05 UTC
Last updated: 07/23/2026, 01:18:05 UTC
Views: 1
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