CVE-2026-44576: Vercel Next.js

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

Next.js is a React framework for building full-stack web applications. From 14.2.0 to before 15.5.16 and 16.2.5, applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML. This vulnerability is fixed in 15.5.16 and 16.2.5.

Affected products

• Vercel Next.js: from 14.2.0, before 15.5.16 (fixed in 15.5.16); from 16.0.0, before 16.2.5 (fixed in 16.2.5)

Published 2026-05-13. Last modified 2026-06-17.