Next.js: Middleware / Proxy bypass in Pages Router applications using i18n

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-44573
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-13 17:16:22 UTC
Updated2026-07-15 02:21:58 UTC
DescriptionNext.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, Applications using the Pages Router with i18n configured and middleware/proxy-based authorization can allow unauthorized access to protected page data through locale-less /_next/data/<buildId>/<page>.json requests. In affected configurations, middleware does not run for the unprefixed data route, allowing an attacker to retrieve SSR JSON for protected pages without passing the intended authorization checks. This vulnerability is fixed in 15.5.16 and 16.2.5.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from ADP

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

EPSS: 0.000520000 probability, percentile 0.162990000 (date 2026-05-21)

Problem Types: CWE-863 | CWE-551 | CWE-863 CWE-863: Incorrect Authorization | CWE-551 Incorrect Behavior Order: Authorization Before Parsing and Canonicalization

VersionSourceTypeScoreSeverityVector
3.1ADPCVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Vercel Next.js All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Vercel Next.js affected >= 12.2.0, < 15.5.16 Not specified
CNA Vercel Next.js affected >= 16.0.0, < 16.2.5 Not specified
ADP Red Hat Streams For Apache Kafka 2.9.4 Not specified Not specified
ADP Red Hat Red Hat Trusted Artifact Signer 1.4 unaffected 1783327185 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 7 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AI RHEL AI 3 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AI RHEL AI 3 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AI RHEL AI 3 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AI RHEL AI 3 Not specified Not specified
ADP Red Hat Streams For Apache Kafka 3 Not specified Not specified

References

ReferenceSourceLinkTags
access.redhat.com/errata/RHSA-2026:37272 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/security/cve/CVE-2026-44573 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:34608 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
bugzilla.redhat.com/show_bug.cgi 0b0ca135-0b70-47e7-9f44-1890c2a1c46c bugzilla.redhat.com
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44573.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com
github.com/vercel/next.js/security/advisories/GHSA-36qx-fr4f-26g5 [email protected] github.com Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
ADP2026-05-13T18:01:50.343ZReported to Red Hat.
ADP2026-05-13T16:48:16.218ZMade public.

Solutions

ADP: RHSA-2026:37272: Red Hat Trusted Artifact Signer 1.4

ADP: RHSA-2026:34608: Streams for Apache Kafka 2.9.4

Workarounds

ADP: 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.

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