Next.js is a React framework for building full-stack web applications. Versions prior to 14.2.24 and 15.1.6 have a race-condition vulnerability. This issue only affects the Pages Router under certain misconfigurations, causing normal endpoints to serve `pageProps` data instead of standard HTML. This issue was patched in versions 15.1.6 and 14.2.24 by stripping the `x-now-route-matches` header from incoming requests. Applications hosted on Vercel's platform are not affected by this issue, as the platform does not cache responses based solely on `200 OK` status without explicit `cache-control` headers. Those who self-host Next.js deployments and are unable to upgrade immediately can mitigate this vulnerability by stripping the `x-now-route-matches` header from all incoming requests at the content development network and setting `cache-control: no-store` for all responses under risk. The maintainers of Next.js strongly recommend only caching responses with explicit cache-control headers.

Affected: npm: next

**Summary** We received a responsible disclosure from Allam Rachid (zhero) for a low-severity race-condition vulnerability in Next.js. This issue only affects the **Pages Router** under certain misconfigurations, causing normal endpoints to serve `pageProps` data instead of standard HTML.

[Learn more here](https://vercel.com/changelog/cve-2025-32421)

**Credit** Thank you to **Allam Rachid (zhero)** for the responsible disclosure. This research was rewarded as part of our bug bounty program.

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Vercel Next.js ausnutzen, um Informationen offenzulegen.