CVE-2025-49826: Vercel Next.js

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

Next.js is a React framework for building full-stack web applications. From versions 15.0.4-canary.51 to before 15.1.8, a cache poisoning bug leading to a Denial of Service (DoS) condition was found in Next.js. This issue does not impact customers hosted on Vercel. Under certain conditions, this issue may allow a HTTP 204 response to be cached for static pages, leading to the 204 response being served to all users attempting to access the page. This issue has been addressed in version 15.1.8.

Affected products

• Vercel Next.js: after 15.0.4, before 15.1.8 (fixed in 15.1.8); version 15.0.4 only

Published 2025-07-03. Last modified 2026-06-17.