CVE-2026-44578

Next.js is a React framework for building full-stack web applications. From 13.4.13 to before 15.5.16 and 16.2.5, self-hosted applications using the built-in Node.js server can be vulnerable to server-side request forgery through crafted WebSocket upgrade requests. An attacker can cause the server to proxy requests to arbitrary internal or external destinations, which may expose internal services or cloud metadata endpoints. Vercel-hosted deployments are not affected. This vulnerability is fixed in 15.5.16 and 16.2.5.

Affected products

Node.Js

Vercel Next.js

< 15.5.16, 16.2.5

Fix

Available

CVSS 3.1

8.6 HIGH

EPSS

38.9% (98th percentile)

Weakness

CWE-918

NVD status

Modified

Published

2026-05-13