CVE-2026-64641: Vercel Next.js

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

Next.js is a React framework for building full-stack web applications. In versions 13.0.0 through 15.5.20 and 16.0.0 through 16.2.10, crafted requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive CPU usage blocking processing of further requests in the same process. This issue has been fixed in versions 15.5.21 and 16.2.11.

Affected products

• Vercel Next.js: from 13.0.0, 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.