ID :ISA-2026-094
Critical alertActiveCVSS 9.0/10IservicesCSIRT

Remote arbitrary code execution affecting Next.js

Executive Summary

A critical vulnerability affecting Next.js would allow an unauthenticated attacker to remotely execute arbitrary code on Windows servers using certain Next.js configurations.

Published on September 1, 2026 at 01:00 AM by Iservices Csirt13 views

Description

Technical context and vulnerability details

Next.js is an open source JavaScript framework based on React, used for developing modern web applications with hybrid rendering, both server-side and client-side. This framework is affected by a vulnerability labeled CVE-2026-75604, resulting from improper handling of file paths under Windows. Exploitation of this vulnerability affecting applications simultaneously using the “Pages Router” and “App Router” modules without cache components, would allow an unauthenticated malicious actor to cause a path traversal that could lead to remote arbitrary code execution. It is classified critical, with a severity score of 9.0 according to CVSS v3.1.

Potential Risks & Impact

Potential consequences upon exploitation

  • Remote Arbitrary Code Execution;
  • Unauthorized access to system files;
  • Breach of confidentiality, integrity and availability of data;

Affected systems

Products, components and targeted versions

  • Applications using Next.js versions 13.4 to 15.5.23 and 16.0 to 16.3.2, when deployed on a Windows server;

Recommended Remediations & Actions

Immediate actions and recommended mitigations

  • Update Next.js to version 15.5.24, 15.5 or 16.3.3, depending on the branch used;

Advisory Specifications

ISA-2026-094
CVSS scoreCRITICAL
9.0/ 10.0
0.0 (Low)5.0 (Med)10.0 (Crit)
PriorityCritical
StatusActive
Typesecurite
Published onSeptember 1, 2026 at 01:00 AM
OrigineIservicesCSIRT
Audience13 views

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