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Fencer Vulns
high 7.5

CVE-2025-31137 json

Remix and React Router allow URL manipulation via Host / X-Forwarded-Host headers

published 2025-04-01 19 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-9433 , GHSA-4q56-crqp-v477

cvss
7.5
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

React Router is a multi-strategy router for React bridging the gap from React 18 to React 19. There is a vulnerability in Remix/React Router that affects all Remix 2 and React Router 7 consumers using the Express adapter. Basically, this vulnerability allows anyone to spoof the URL used in an incoming Request by putting a URL pathname in the port section of a URL that is part of a Host or X-Forwarded-Host header sent to a Remix/React Router request handler. This issue has been patched and released in Remix 2.16.3 and React Router 7.4.1.

Patch / fix

  • npm @react-router/express 7.4.1
  • npm @remix-run/express 2.16.3
  • shopify react-router/express 7.4.1
  • shopify remix-run/express 2.16.3

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-31137 updated cvss 7.5

react-router: Remix Host Header Spoofing Vulnerability

  • Red Hat OpenShift AI (RHOAI) rhoai/odh-dashboard-rhel8
    affected: workaround, no fix available
  • Red Hat Cryostat 4 io.cryostat-cryostat Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/kibana6-rhel8 Red Hat Migration Toolkit for Applications 7 mta/mta-ui-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-ui-rhel8 Red Hat Migration Toolkit for Virtualization mtv-candidate/mtv-console-plugin-rhel9, migration-toolkit-virtualization/mtv-console-plugin-rhel9 Red Hat Multicluster Engine for Kubernetes multicluster-engine/console-mce-rhel8, multicluster-engine/console-mce-rhel9
    +30 more products
    Red Hat Network Observability Operator network-observability/network-observability-console-plugin-rhel9 Red Hat OpenShift Pipelines openshift-pipelines/pipelines-hub-ui-rhel8, openshift-pipelines/pipelines-hub-ui-rhel9, openshift-pipelines/pipelines-hub-api-rhel8, openshift-pipelines/pipelines-hub-api-rhel9, openshift-pipelines/pipelines-console-plugin-rhel8, openshift-pipelines/pipelines-console-plugin-rhel9, +2 more Red Hat OpenShift Serverless openshift-serverless-1/kn-backstage-plugins-eventmesh-rhel8 Red Hat OpenShift Service Mesh 2 openshift-service-mesh/kiali-rhel8, openshift-service-mesh/kiali-ossmc-rhel8 Red Hat OpenShift Service Mesh 3 openshift-service-mesh/kiali-rhel8, openshift-service-mesh/kiali-rhel9, openshift-service-mesh/kiali-ossmc-rhel8, openshift-service-mesh/kiali-ossmc-rhel9, openshift-service-mesh/kiali-rhel9-operator, openshift-service-mesh/kiali-operator-bundle Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/console-rhel9, rhacm2/acm-flightctl-ui-rhel9, rhacm2/acm-flightctl-ocp-ui-rhel9 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-main-rhel8, advanced-cluster-security/rhacs-roxctl-rhel8, advanced-cluster-security/rhacs-rhel8-operator, advanced-cluster-security/rhacs-central-db-rhel8, advanced-cluster-security/rhacs-scanner-v4-rhel8, advanced-cluster-security/rhacs-scanner-v4-db-rhel8 Red Hat Ansible Automation Platform 2 automation-hub, python-galaxy-ng, automation-gateway, python3x-galaxy-ng, automation-controller, aap-cloud-ui-container, +1 more Red Hat build of Apache Camel - HawtIO 4 io.hawt-project Red Hat build of Apicurio Registry 2 io.apicurio-apicurio-registry Red Hat build of OptaPlanner 8 org.optaweb.vehiclerouting-optaweb-vehicle-routing Red Hat Data Grid 8 org.infinispan-infinispan-console Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9, rhdh/rhdh-rhel9-operator Red Hat Discovery 1 discovery/discovery-ui-rhel9 Red Hat Edge Manager preview rhem/flightctl-ui-rhel9, rhem/flightctl-ui-ocp-rhel9, rhacm2/acm-flightctl-ui-rhel9, rhacm2/acm-flightctl-ocp-ui-rhel9 Red Hat Enterprise Linux 8 dotnet5.0-build-reference-packages Red Hat Fuse 7 io.syndesis-syndesis-parent Red Hat Integration Camel K 1 io.apicurio-apicurio-registry Red Hat JBoss Enterprise Application Platform 8 org.keycloak-keycloak-parent Red Hat JBoss Enterprise Application Platform Expansion Pack org.keycloak-keycloak-parent Red Hat OpenShift AI (RHOAI) rhoai/odh-rhel8-operator, rhods/odh-rhel8-operator, rhoai/odh-model-registry-rhel8, rhoai/odh-data-science-pipelines-argo-argoexec-rhel8, rhoai/odh-data-science-pipelines-argo-workflowcontroller-rhel8 Red Hat OpenShift Container Platform 4 openshift4/ose-console, openshift4/ose-console-rhel9, openshift4/ose-monitoring-plugin-rhel8, openshift4/ose-monitoring-plugin-rhel9 Red Hat Openshift Data Foundation 4 odf4/odf-console-rhel9, odf4/ocs-client-console-rhel9, odf4/odf-multicluster-console-rhel9 Red Hat OpenShift Dev Spaces devspaces/dashboard-rhel8, devspaces/dashboard-rhel9 Red Hat OpenShift GitOps openshift-gitops-1/argocd-rhel8, openshift-gitops-1/argocd-rhel9, openshift-gitops-1/argo-rollouts-rhel8, openshift-gitops-1/console-plugin-rhel8, openshift-gitops-1/gitops-operator-bundle Red Hat OpenShift Virtualization 4 container-native-virtualization/kubevirt-console-plugin, container-native-virtualization/kubevirt-console-plugin-rhel9 Red Hat Process Automation 7 org.uberfire-uberfire-parent Red Hat Quay 3 quay/quay-rhel8 Red Hat Single Sign-On 7 org.keycloak-keycloak-parent Red Hat Trusted Profile Analyzer rhtpa/rhtpa-trustification-service-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
19 mo ago

Exploit prediction

1.19% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm @react-router/express
>=7.0.0, <7.4.1
7.4.1
npm @remix-run/express
>=2.11.1, <2.16.3
2.16.3

Affected products

  • remix-run react-router

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.