CVE-2026-94482: Next.js: Denial of Service in App Router using Server Actions

Severity: high (CVSS 8.2 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-22 · updated 2026-10-30
Weakness: CWE-770

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.

Affected products

Npm Next: from 13.0.0 before 15.5.28; from 16.0.0 before 16.4.1 — fixed in 15.5.28, 16.4.1
Next.js: from 13.0.0, < 15.5.28; from 16.0.0, < 16.4.1

How to fix

Upgrade to a fixed version: Npm Next 15.5.28, 16.4.1. Check the vendor advisory for mitigations.

References

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