CVE-2026-64642

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

Published Jul 27, 2026 CVSS 4.0 · 8.3 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-6gpp-xcg3-4w24 Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale
History
Type Values Removed Values Added
Weaknesses CWE-807
References
Metrics threat_severity

None

cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N'}

threat_severity

Important

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Vercel
Vercel next.js
Vendors & Products Vercel
Vercel next.js
Type Values Removed Values Added
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.
Title Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale
Weaknesses CWE-285
References
Metrics cvssV4_0

{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 28, 2026, 3:20 PM
Reserved
Jul 20, 2026, 5:11 PM
Status
Analyzed
Published
Jul 27, 2026, 6:16 PM
Modified
Oct 24, 2026, 1:10 PM
Severity
Important
Public date
Jul 27, 2026, 5:45 PM