CVE-2026-44574
Next.js: Middleware / Proxy bypass through dynamic route parameter injection
CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-288 |
| Vendor | vercel |
| Product | next.js |
| Published | May 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
vercel / next.js
>= 15.4.0, < 15.5.16 >= 16.0.0, < 16.2.5