Next.js: Denial of Service in App Router using Server Actions

ALTO 8.2CVE-2026-94482 · GHSA-p3m5-59mp-jv5r · Published 22/10/2026 · updated 22/10/2026

Package	Affected versions	Patched versions
next npm	`≥ 13.0.0, < 15.5.28≥ 16.0.0, < 16.4.1`	`15.5.2816.4.1`

Description

Impact

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.

Workarounds

No workaround exists besides upgrading. Applications using Pages Router or not using Server Actions are not vulnerable.

NVD description

Next.js is a React framework for building full-stack web applications. From 13.0.0 until 15.5.28 and 16.4.1, crafted requests targeting App Router applications with at least one Server Action can cause excessive CPU consumption and block processing of further requests in the same process. Applications using the Pages Router and App Router applications without Server Actions are not affected. This issue is fixed in versions 15.5.28 and 16.4.1.

References

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