Skip to content
Fencer Vulns
high 8.6

CVE-2026-55602 json

http-proxy-middleware `router` host+path substring matching allows Host-header-driven backend routing bypass

published 2026-06-18 4 mo ago modified 2026-10-25 14 d ago also GHSA-64mm-vxmg-q3vj , EUVD-2026-38300

cvss
8.6
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

http-proxy-middleware is node.js http-proxy middleware. From 0.16.0 until 2.0.10, 3.0.6, and 4.1.0, http-proxy-middleware documents router proxy-table entries as host, path, or host+path selectors, but the host+path implementation uses unanchored substring matching on attacker-controlled request metadata. As a result, a crafted Host header that is only a superstring match for a configured host+path key can still route a request to an unintended backend. This vulnerability is fixed in 2.0.10, 3.0.6, and 4.1.0.

Patch / fix

  • npm http-proxy-middleware 2.0.10, 3.0.6, 4.1.0
  • chimurai http-proxy-middleware 2.0.10, 3.0.6, 4.1.0
  • velociraptor openSUSE Tumbleweed 0.76.7.0.git145.b60ef1146-1.1
  • agama-web-ui openSUSE Tumbleweed 24+0.a836cced5-52.1
  • agama-web-ui openSUSE Leap 16.0 17+673.b97ba64d6-160000.12.1

opensuse advisories openSUSE-SU-2026:12070-1openSUSE-SU-2026:11680-1openSUSE-SU-2026:21448-1

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-2026-55602 updated cvss 6.5

http-proxy-middleware: http-proxy-middleware: Unintended backend routing due to crafted Host header

  • Red Hat Cryostat 4 http-proxy-middleware, cryostat-openshift-console-plugin-npm Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-ui-rhel8, mta/mta-ui-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-ui-rhel8 Red Hat Node HealthCheck Operator workload-availability/node-healthcheck-rhel9-operator, workload-availability/node-healthcheck-operator-bundle, workload-availability/node-healthcheck-must-gather-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-console-plugin-rhel9, openshift-lightspeed/lightspeed-console-plugin-419-rhel9, openshift-lightspeed/lightspeed-console-plugin-pf5-rhel9
    +24 more products
    Red Hat OpenShift Pipelines openshift-pipelines/pipelines-hub-ui-rhel8, openshift-pipelines/pipelines-hub-ui-rhel9, openshift-pipelines/pipelines-console-plugin-rhel8, openshift-pipelines/pipelines-console-plugin-rhel9, openshift-pipelines/pipelines-console-plugin-pf5-rhel9 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-rhel9, openshift-service-mesh/kiali-ossmc-rhel9, openshift-service-mesh/kiali-rhel9-operator, openshift-service-mesh/kiali-operator-bundle Red Hat AMQ Broker 7 http-proxy-middleware Red Hat Ansible Automation Platform 2 automation-eda-controller, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-27/gateway-rhel9, ansible-automation-platform-24/lightspeed-rhel8, ansible-automation-platform-25/lightspeed-rhel8, ansible-automation-platform-26/lightspeed-rhel9, +1 more Red Hat build of Apache Camel - HawtIO 4 http-proxy-middleware Red Hat build of Apache Camel for Spring Boot 4 http-proxy-middleware Red Hat Build of Podman Desktop rh-podman-desktop.git Red Hat Connectivity Link 1 rhcl-1/rhcl-console-plugin-rhel9 Red Hat Data Grid 8 http-proxy-middleware Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9 Red Hat Discovery 2 discovery/discovery-ui-rhel9 Red Hat Enterprise Linux 8 pcs, pcs-snmp Red Hat Enterprise Linux 9 pcs, pcs-snmp Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-gaudi-rhel9, rhelai3/disk-image-cuda-rhel9 Red Hat Fuse 7 http-proxy-middleware Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9 Red Hat OpenShift Container Platform 4 openshift4/ose-console, openshift4/ose-console-rhel9, openshift4/ose-agent-installer-ui-rhel9 Red Hat OpenShift Container Platform 5 openshift5/ose-console-rhel9, openshift5/ose-agent-installer-ui-rhel9 Red Hat OpenShift Virtualization 4 container-native-virtualization/kubevirt-console-plugin, container-native-virtualization/kubevirt-console-plugin-rhel9 Red Hat Quay 3 quay/quay-rhel8 Red Hat Trusted Artifact Signer rhtas/rhtas-console-ui-rhel9 Red Hat Trusted Profile Analyzer rhtpa/rhtpa-trustification-service-rhel9 Red Hat Self-service automation portal 2 ansible-automation-platform/automation-portal, ansible-automation-platform/bootc-automation-portal-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
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/chimurai/http-proxy-middleware/security/advisories/GHSA-64mm-vxmg-q3vj referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
npm http-proxy-middleware
>=3.0.0, <3.0.6
>=4.0.0, <4.1.0
>=0.16.0, <2.0.10
3.0.6
4.1.0
2.0.10

Affected products

  • chimurai http-proxy-middleware

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-187 Partial String Comparison

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.