chimurai http-proxy-middleware up to 2.0.9/3.0.5/4.0.x Host input validation

Summaryinfo

A vulnerability, which was classified as problematic, was found in chimurai http-proxy-middleware up to 2.0.9/3.0.5/4.0.x. Affected by this issue is some unknown functionality of the component Host Handler. The manipulation results in input validation. This vulnerability is known as CVE-2026-55602. It is possible to launch the attack remotely. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in chimurai http-proxy-middleware up to 2.0.9/3.0.5/4.0.x. Affected is some unknown functionality of the component Host Handler. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-55602 since 06/17/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available.

Upgrading to version 2.0.10, 3.0.6 or 4.1.0 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Middleware

Vendor

• chimurai

Name

• http-proxy-middleware

Version

• 2.0.0
• 2.0.1
• 2.0.2
• 2.0.3
• 2.0.4
• 2.0.5
• 2.0.6
• 2.0.7
• 2.0.8
• 2.0.9
• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 4.0

Website

• Product: https://github.com/chimurai/http-proxy-middleware/

CPE 2.3info

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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