# CVE-2026-55602

## Summary

- **CVE ID:** CVE-2026-55602
- **Severity:** MEDIUM
- **CVSS Score:** 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)
- **CWE:** CWE-20, CWE-187
- **Published:** Jun 22, 2026
- **Last Modified:** Jun 23, 2026

## 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.

## Affected Products

- chimurai — http-proxy-middleware (>= 4.0.0, < 4.1.0)
- chimurai — http-proxy-middleware (>= 3.0.0, < 3.0.6)
- chimurai — http-proxy-middleware (>= 0.16.0, < 2.0.10)

## References

- [CNA](https://github.com/chimurai/http-proxy-middleware/security/advisories/GHSA-64mm-vxmg-q3vj)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.37%
- **EPSS Percentile:** 30.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._