Next.js: Middleware / Proxy bypass through dynamic route parameter injection
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · 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-288.
Summary
Next.js is a React framework for building full-stack web applications. From 15.4.0 to before 15.5.16 and 16.2.5, applications that rely on middleware to protect dynamic routes can be vulnerable to authorization bypass. In affected deployments, specially crafted query parameters can alter the dynamic route value seen by the page while leaving the visible path unchanged, which can allow protected content to be rendered without passing the expected middleware check. This vulnerability is fixed in 15.5.16 and 16.2.5.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| vercel | next.js | 15.4.0 to before 15.5.16; 16.0.0 to before 16.2.5 | 15.5.16, 16.2.5 | Patch available | CNA |
| — | next (npm) | 15.4.0 to before 15.5.16 | 15.5.16 | Patch available | GHSA-492v-c6pp-mqqv |
| — | next (npm) | 16.0.0 to before 16.2.5 | 16.2.5 | Patch available | GHSA-492v-c6pp-mqqv |
- next.js Vendorvercel Affected 15.4.0 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 15.4.0 to before 15.5.16 Fixed in 15.5.16 Patch available GHSA-492v-c6pp-mqqv
- next (npm) Vendor— Affected 16.0.0 to before 16.2.5 Fixed in 16.2.5 Patch available GHSA-492v-c6pp-mqqv
Remediation
- Fix · CNA next.js (vercel) Fixed in 15.5.16, 16.2.5
- Fix · GHSA-492v-c6pp-mqqv next (npm) Fixed in 15.5.16 Advisory →
- Fix · GHSA-492v-c6pp-mqqv next (npm) Fixed in 16.2.5 Advisory →
Red Hat 4 advisories
- RHSA-2026:54435 Released 2026-08-12 · Red Hat rating ImportantStreams 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 ImportantRHTAS 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 ImportantRHTAS 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 ImportantStreams 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 →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix planned: Will not fix |
| Red Hat Trusted Artifact Signer 1.3 | Fixed | RHSA-2026:40974 |
| Red Hat Trusted Artifact Signer 1.4 | Fixed | RHSA-2026:37272 |
| Streams for Apache Kafka 2.9.4 | Fixed | RHSA-2026:34608 |
| Streams for Apache Kafka 3.2.1 | Fixed | 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
- 2026-10-02 Threatist record created from CVE-2026-44574
- 2026-10-03 Alias added: GHSA-492v-c6pp-mqqv
References
More vercel Next.js vulnerabilities
- 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
Sources
- CVE-2026-44574 · CVE Program
- CVE-2026-44574 · NVD
- FIRST EPSS
- GHSA-492v-c6pp-mqqv · GitHub Advisory Database · CC BY 4.0
- CVE-2026-44574 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences