CVE-2026-55602
Description
A flaw was found in http-proxy-middleware (before 2.0.10, 3.0.6, and 4.1.0). Router proxy-table host+path matching uses unanchored substring comparison on the Host header, so a crafted Host value that superstring-matches a configured key can route requests to an unintended backend.
Statement
http-proxy-middleware is vulnerable to unintended backend routing when host+path proxy-table entries are configured. Unanchored substring matching on the attacker-controlled Host header can match a configured host+path key without an exact host match, sending the request to the wrong backend. Red Hat exposure is in Node.js dev/proxy stacks that bundle the middleware for local or console plugin routing, including OpenShift console plugins, Cryostat, GitOps, and AAP Lightspeed where reverse proxy rules use host+path selectors.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | 8.6 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Changed | N/A |
| Confidentiality | Low | None | N/A |
| Integrity Impact | Low | High | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
An attacker can access any functionality that is inadvertently accessible to the source.
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