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TI-2026-32485 Aliases CVE-2026-44573GHSA-36qx-fr4f-26g5

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

Priority MEDIUM 40CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 4 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-863.

Summary

Next.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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00796 56th percentileScored 2026-11-07
Fix Partial next.js (vercel): 15.5.16, 16.2.5next (npm): 15.5.16, 16.2.5Red Hat: 4 advisoriesRed Hat: 4 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
vercelnext.js12.2.0 to before 15.5.16; 16.0.0 to before 16.2.515.5.16, 16.2.5Patch availableCNA
—next (npm)12.2.0 to before 15.5.1615.5.16Patch availableGHSA-36qx-fr4f-26g5
—next (npm)16.0.0 to before 16.2.516.2.5Patch availableGHSA-36qx-fr4f-26g5
  • next.js Vendorvercel Affected 12.2.0 to before 15.5.16; 16.0.0 to before 16.2.5 Fixed in 15.5.16, 16.2.5 Patch available CNA
  • next (npm) Vendor— Affected 12.2.0 to before 15.5.16 Fixed in 15.5.16 Patch available GHSA-36qx-fr4f-26g5
  • next (npm) Vendor— Affected 16.0.0 to before 16.2.5 Fixed in 16.2.5 Patch available GHSA-36qx-fr4f-26g5

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*12.2.0 to before 15.5.16; 16.0.0 to before 16.2.5Vulnerablevercel
  • cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:* Versions 12.2.0 to before 15.5.16; 16.0.0 to before 16.2.5 Vulnerable ·vercel

Remediation

  • Fix · CNA next.js (vercel) Fixed in 15.5.16, 16.2.5
  • Fix · GHSA-36qx-fr4f-26g5 next (npm) Fixed in 15.5.16 Advisory →
  • Fix · GHSA-36qx-fr4f-26g5 next (npm) Fixed in 16.2.5 Advisory →

Red Hat 4 advisories

  • RHSA-2026:54435 Released 2026-08-12 · Red Hat rating Important
    Streams for Apache Kafka 3.2.1 release and security update
    • Streams for Apache Kafka 3.2.1
  • RHSA-2026:40974 Released 2026-07-16 · Red Hat rating Important
    RHTAS 1.3.6 - Red Hat Trusted Artifact Signer Release
    • Red Hat Trusted Artifact Signer 1.3 registry.redhat.io/rhtas/certificate-transparency-rhel9, registry.redhat.io/rhtas/fulcio-rhel9, registry.redhat.io/rhtas/rekor-backfill-redis-rhel9 +6
  • RHSA-2026:37272 Released 2026-07-09 · Red Hat rating Important
    RHTAS 1.4.2 - Red Hat Trusted Artifact Signer Release
    • Red Hat Trusted Artifact Signer 1.4 registry.redhat.io/rhtas/certificate-transparency-rhel9, registry.redhat.io/rhtas/fulcio-rhel9, registry.redhat.io/rhtas/rekor-backfill-redis-rhel9 +6
Show 1 more Red Hat advisories
  • RHSA-2026:34608 Released 2026-07-02 · Red Hat rating Important
    Streams for Apache Kafka 2.9.4 release and security update
    • Streams for Apache Kafka 2.9.4

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix planned: Will not fix
Red Hat Trusted Artifact Signer 1.3Fixed RHSA-2026:40974
Red Hat Trusted Artifact Signer 1.4Fixed RHSA-2026:37272
Streams for Apache Kafka 2.9.4Fixed RHSA-2026:34608
Streams for Apache Kafka 3.2.1Fixed RHSA-2026:54435
Not affected: 6 products
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat Trusted Artifact Signer 1.3
  • Red Hat Trusted Artifact Signer 1.4

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-44573
  2. 2026-10-03 Alias added: GHSA-36qx-fr4f-26g5

References

Advisory 2

Other 3

  • TI-2025-34861 Deserialization of untrusted data in Meta react-server-dom-webpack KEVCVSS 3.1CRITICAL 10.0
  • TI-2025-21309 Authorization Bypass in Next.js Middleware CVSS 3.1CRITICAL 9.1
  • TI-2025-34863 Deserialization of untrusted data in Meta react-server-dom-webpack CVSS 3.1HIGH 7.5
  • TI-2024-31371 Cache Poisoning in next.js CVSS 3.1HIGH 7.5
  • TI-2023-24914 Next.js before 13.4.20-canary.13 lacks a cache-control header and thus empty prefetch… CVSS 3.1HIGH 7.5
  • TI-2026-32490 Next.js: Server-side request forgery in applications using WebSocket upgrades CVSS 3.1HIGH 8.6
See all 62 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences