CVE-2026-44575
Next.js: Middleware / Proxy bypass in App Router applications via segment-prefetch routes
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.16 and 16.2.5, App Router applications that rely on middleware or proxy-based checks for authorization can allow unauthorized access through transport-specific route variants used for segment prefetching. In affected configurations, specially crafted .rsc and segment-prefetch URLs can resolve to the same page without being matched by the intended middleware rule, which can allow protected content to be reached without the expected authorization 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 |
| Last Updated | May 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
vercel / next.js
>= 16.0.0, < 16.2.5 >= 15.2.0, < 15.5.16