CVE-2026-64645: Vercel Next.js

Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days.

Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a rewrites() or redirects() rule that builds its external destination hostname from request-controlled input can be pointed at an arbitrary hostname, regardless of the rule's hostname suffix. For a rewrite, Next.js proxies the request to that arbitrary host and serves the response from the application's origin, leading to Server-Side Request forgery. A redirects() rule configured this way is vulnerable to an Open Redirect. This issue has been fixed in versions 15.5.21 and 16.2.11.

Affected products

• Vercel Next.js: from 12.0.0, before 15.5.21 (fixed in 15.5.21); from 16.0.0, before 16.2.11 (fixed in 16.2.11)

Published 2026-07-27. Last modified 2026-07-29.