CVE-2026-44574 HIGH

CVE-2026-44574: Next.js: Middleware / Proxy bypass through dynamic route parameter injection

Vendor Vercel
Product next.js
Weakness CWE-288
Published May 13, 2026
Last update June 30, 2026

CVSS base score

8.1/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

What the vulnerability does

01Description

Next.js is a React framework for building full-stack web applications. From 15.4.0 to before 15.5.16 and 16.2.5, applications that rely on middleware to protect dynamic routes can be vulnerable to authorization bypass. In affected deployments, specially crafted query parameters can alter the dynamic route value seen by the page while leaving the visible path unchanged, which can allow protected content to be rendered without passing the expected middleware check. This vulnerability is fixed in 15.5.16 and 16.2.5.

Key dates

02Disclosure timeline

May 13, 2026 CVE published
June 30, 2026 Record updated