CVE-2026-44575
Next.js: Middleware / Proxy bypass in App Router applications via segment-prefetch routes
HIGH 7.5
At a glance
- Source
- NVD
- EPSS
- EPSS 1.59 % · percentile 76 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Modified
Description
Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.16 and 16.2.5, App Router applications that rely on middleware or proxy-based checks for authorization can allow unauthorized access through transport-specific route variants used for segment prefetching. In affected configurations, specially crafted .rsc and segment-prefetch URLs can resolve to the same page without being matched by the intended middleware rule, which can allow protected content to be reached without the expected authorization check. This vulnerability is fixed in 15.5.16 and 16.2.5.
Weaknesses (CWE)
- CWE-288 — Authentication Bypass Using an Alternate Path or Channel
- CWE-551 — Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
References
- https://github.com/vercel/next.js/security/advisories/GHSA-267c-6grr-h53f
- https://access.redhat.com/security/cve/CVE-2026-44575
- https://bugzilla.redhat.com/show_bug.cgi?id=2477188
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44575.json
- https://access.redhat.com/errata/RHSA-2026:40974
- https://access.redhat.com/errata/RHSA-2026:37272
- https://access.redhat.com/errata/RHSA-2026:34608
- https://access.redhat.com/errata/RHSA-2026:54435
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | GitHub_M |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | redhat-SADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Advisories
- GHSA-267c-6grr-h53f — Next.js has a Middleware / Proxy bypass in App Router applications via segment-prefetch routes
European references
- ENISA EUVD · EUVD-2026-30059
- GCVE · GCVE-0-2026-44575
CERT-FR advisories
- CERTFR-2026-AVI-0901 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*≥ 15.2.0 < 15.5.16cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*≥ 16.0.0 < 16.2.5
Affected products
| Product | Versions |
|---|---|
| vercel · next.js | affected >= 16.0.0, < 16.2.5 ; affected >= 15.2.0, < 15.5.16 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |