Skip to content
Fencer Intel
high 8.6

CVE-2026-55602 json

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

published 4mo ago modified 17d ago also EUVD-2026-38300 , GHSA-64mm-vxmg-q3vj

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 32%
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

Is CVE-2026-55602 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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
4mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-11).

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 Intel 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.

The maintainers of chimurai/http-proxy-middleware published their own advisory on GitHub. Reviewed sources take precedence over it.

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