Acceptance of Extraneous Untrusted Data With Trusted Data in Next.js - #VU130282
Published: May 6, 2026
Vulnerability identifier: #VU130282
CSH Severity: Low
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-349
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Next.js
Next.js
Software vendor:
vercel
vercel
Description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to acceptance of extraneous untrusted data with trusted data in middleware / proxy redirect handling when processing a normal request with a spoofed x-nextjs-data header on a path that returns a redirect. A remote attacker can send a specially crafted request to cause a denial of service.
Exploitation requires the application to be deployed behind a caching CDN or reverse proxy that caches 3xx responses for the affected path without varying on the x-nextjs-data header.
Remediation
Install security update from vendor's website.