CVE-2026-44573

Description

A flaw was found in Next.js. Applications utilizing the Pages Router with internationalization (i18n) configured and middleware or proxy-based authorization are susceptible to unauthorized access. A remote attacker can exploit this by making locale-less /_next/data//.json requests, which bypass the intended authorization checks. This allows the attacker to retrieve sensitive server-side rendered (SSR) JSON data from protected pages, leading to information disclosure.

Statement

Important: A flaw in Next.js applications allows unauthorized access to sensitive server-side rendered (SSR) JSON data by bypassing middleware authorization checks. This occurs when applications use the Pages Router with internationalization (i18n) and middleware or proxy-based authorization, enabling remote attackers to retrieve protected page data through locale-less requests.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score7.5N/A7.5
Attack VectorNetworkN/ANetwork
Attack ComplexityLowN/ALow
Privileges RequiredNoneN/ANone
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityHighN/AHigh
Integrity ImpactNoneN/ANone
Availability ImpactNoneN/ANone

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Understanding the Weakness (CWE)

Access Control

Technical Impact: Bypass Protection Mechanism

Frequently Asked Questions

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