CVE-2026-55602
http-proxy-middleware `router` host+path substring matching allows Host-header-driven backend routing bypass
MEDIUM 6.9
At a glance
- Source
- NVD
- EPSS
- EPSS 0.38 % · percentile 32 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 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 | GitHub_M |
| CVSS 4.0 | MEDIUM 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 · security-advisories@github.com (Secondary) |
| CVSS 3.1 | HIGH 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-64mm-vxmg-q3vj — http-proxy-middleware `router` host+path substring matching allows Host-header-driven backend routing bypass
European references
- ENISA EUVD · EUVD-2026-38300
- GCVE · GCVE-0-2026-55602
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1233 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:chimurai:http-proxy-middleware:*:*:*:*:*:*:*:*≥ 0.16.0 < 2.0.10cpe:2.3:a:chimurai:http-proxy-middleware:*:*:*:*:*:*:*:*≥ 3.0.0 < 3.0.6cpe:2.3:a:chimurai:http-proxy-middleware:*:*:*:*:*:*:*:*≥ 4.0.0 < 4.1.0
Affected products
| Product | Versions |
|---|---|
| chimurai · http-proxy-middleware | affected >= 4.0.0, < 4.1.0 ; affected >= 3.0.0, < 3.0.6 ; affected >= 0.16.0, < 2.0.10 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |