Deserialization of untrusted data in remix-run react-router
Priority LOW 37CWE-502Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 6 fixed, 8 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-502.
Summary
React Router is a router for React. In versions 7.0.0 through 7.14.1, when using Framework Mode, a combination of steps could potentially allow unauthorized remote code execution (RCE) through external requests. This attack requires the application code to have an existing prototype pollution vulnerability, which can then be leveraged in a 2-step attack where the second step triggers unauthorized RCE on the remote server. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.14.2.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00416 36th percentileScored 2026-11-07
Fix Partial react-router (remix-run): 7.14.2react-router (npm): 7.14.2Red Hat: 7 advisoriesRed Hat: 6 fixed, 8 without a fix
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 |
|---|---|---|---|---|---|
| remix-run | react-router | 7.0.0 to before 7.14.2 | 7.14.2 | Patch available | CNA |
| — | react-router (npm) | 7.0.0 to before 7.14.2 | 7.14.2 | Patch available | GHSA-49rj-9fvp-4h2h |
- react-router Vendorremix-run Affected 7.0.0 to before 7.14.2 Fixed in 7.14.2 Patch available CNA
- react-router (npm) Vendor— Affected 7.0.0 to before 7.14.2 Fixed in 7.14.2 Patch available GHSA-49rj-9fvp-4h2h
Remediation
- Fix · CNA react-router (remix-run) Fixed in 7.14.2
- Fix · GHSA-49rj-9fvp-4h2h react-router (npm) Fixed in 7.14.2 Advisory →
Red Hat 7 advisories
- RHSA-2026:84734 Released 2026-10-19 · Red Hat rating CriticalRHOAI 3.4.5 - Red Hat OpenShift AI
- Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-ai-gateway-payload-processing-rhel9, registry.redhat.io/rhoai/odh-automl-rhel9, registry.redhat.io/rhoai/odh-autorag-rhel9 +47
- RHSA-2026:68277 Released 2026-09-16 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.7 Images Security Update
- Red Hat build of Keycloak 26.6 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
- RHSA-2026:68278 Released 2026-09-16 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.7 Security Update
- Red Hat build of Keycloak 26.6.7
Show 4 more Red Hat advisories
- RHSA-2026:60520 Released 2026-08-27 · Red Hat rating CriticalRHOAI 3.4.4 - Red Hat OpenShift AI
- Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-automl-rhel9, registry.redhat.io/rhoai/odh-autorag-rhel9, registry.redhat.io/rhoai/odh-built-in-detector-rhel9 +47
- RHSA-2026:42085 Released 2026-07-20 · Red Hat rating ImportantRHTAS 1.3.6 - Red Hat Trusted Artifact Signer Release
- Red Hat Trusted Artifact Signer 1.3 registry.redhat.io/rhtas/rhtas-console-ui-rhel9
- RHSA-2026:41951 Released 2026-07-20 · Red Hat rating ImportantRed Hat Data Grid 8.6.2 security update
- Red Hat Data Grid 8.6.2
- RHSA-2026:29770 Released 2026-06-25 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images opentelemetry-collector-contrib-0.155.0-0.1.hum1@aarch64, opentelemetry-collector-contrib-0.155.0-0.1.hum1@src, opentelemetry-collector-contrib-0.155.0-0.1.hum1@x86_64
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Pipelines | Affected | No fix yet |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet |
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Process Automation 7 | Affected | No fix planned: Out of support scope |
| Red Hat Single Sign-On 7 | Affected | No fix planned: Will not fix |
| Red Hat build of Apache Camel - HawtIO 4 | Affected | No fix yet |
| Red Hat build of Apicurio Registry 2 | Affected | No fix yet |
| Red Hat build of Apicurio Registry 3 | Affected | No fix yet |
| Red Hat Data Grid 8.6.2 | Fixed | RHSA-2026:41951 |
| Red Hat Hardened Images | Fixed | RHSA-2026:29770 |
| Red Hat OpenShift AI 3.4 | Fixed | RHSA-2026:60520, RHSA-2026:84734 |
| Red Hat Trusted Artifact Signer 1.3 | Fixed | RHSA-2026:42085 |
| Red Hat build of Keycloak 26.6 | Fixed | RHSA-2026:68277 |
| Red Hat build of Keycloak 26.6.7 | Fixed | RHSA-2026:68278 |
Not affected: 46 products
- Cryostat 4
- Exploit Intelligence
- Gatekeeper 3
- Migration Toolkit for Applications 8
- Migration Toolkit for Containers
- Migration Toolkit for Virtualization
- Multicluster Engine for Kubernetes
- Network Observability Operator
- Node HealthCheck Operator
- OpenShift Lightspeed
- OpenShift Pipelines
- OpenShift Service Mesh 2
- OpenShift Service Mesh 3
- Red Hat AMQ Broker 7
- Red Hat Advanced Cluster Management for Kubernetes 2
- Red Hat Advanced Cluster Security 4
- Red Hat Ansible Automation Platform 2
- Red Hat Build of Podman Desktop
- Red Hat Ceph Storage 5
- Red Hat Ceph Storage 9
- Red Hat Connectivity Link 1
- Red Hat Developer Hub 1
- Red Hat Discovery 2
- Red Hat Edge Manager 1
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat Fuse 7
- Red Hat Hardened Images
- Red Hat JBoss Enterprise Application Platform 8
- Red Hat JBoss Enterprise Application Platform Expansion Pack
- Red Hat OpenShift AI (RHOAI)
- Red Hat OpenShift AI 3.4
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
- Red Hat OpenShift Dev Spaces
- Red Hat OpenShift GitOps
- Red Hat OpenShift Virtualization 4
- Red Hat OpenShift distributed tracing 3
- Red Hat Openshift Data Foundation 4
- Red Hat Quay 3
- Red Hat Satellite 6
- Red Hat Trusted Artifact Signer 1.3
- Red Hat Trusted Profile Analyzer
- Red Hat build of Apache Camel for Spring Boot 4
- Self-service automation portal 2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42211
- 2026-10-03 Alias added: GHSA-49rj-9fvp-4h2h
- 2026-10-16 Affected versions changed · Red Hat
- 2026-10-20 Fix available: RHSA-2026:84734 · Red Hat
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-27 Affected versions changed · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
References
More remix-run React-router vulnerabilities
- TI-2026-40200 React Router: Unauthenticated Denial of Service via Inefficient Route Matching CVSS 4.0HIGH 8.7
- TI-2026-30645 React Router vulnerable to DoS via unbounded path expansion in __manifest endpoint CVSS 3.1HIGH 7.5
- TI-2026-26400 React Router vulnerable to Denial of Service via reflected user input in single-fetch CVSS 3.1HIGH 7.5
- TI-2026-17723 React Router vulnerable to XSS via Open Redirects CVSS 3.1HIGH 8.0
- TI-2026-17585 React Router SSR XSS in ScrollRestoration CVSS 3.1HIGH 8.2
- TI-2026-28995 Open redirect in remix-run react-router CVSS 4.0MEDIUM 6.6
Sources
- CVE-2026-42211 · CVE Program
- CVE-2026-42211 · NVD
- FIRST EPSS
- GHSA-49rj-9fvp-4h2h · GitHub Advisory Database · CC BY 4.0
- CVE-2026-42211 · 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