CVE-2026-64641Next.js: Denial of Service in App Router using Server Actions

Description

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.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://github.com/vercel/next.js/security/advisories/GHSA-m99w-x7hq-7vfj Vendor Advisory
• https://github.com/vercel/next.js/pull/96013 Issue TrackingPatch
• https://github.com/vercel/next.js/commit/019628571641dec57aaf349ba0c360e3964e6f12 Patch
• https://github.com/vercel/next.js/releases/tag/v15.5.21 ProductRelease Notes
• https://github.com/vercel/next.js/releases/tag/v16.2.11 ProductRelease Notes