---
id: CVE-2026-77711
title: >-
  When Jetty's `HttpClient` make a request to a server through a forward proxy,
  the server may reply with a 407 (Proxy Authentication Required).




  The client mistakenly interprets the 407 as coming from the proxy, so it
  re-sends the reque…
summary: >-
  When Jetty's `HttpClient` make a request to a server through a forward proxy,
  the server may reply with a 407 (Proxy Authentication Required).




  The client mistakenly interprets the 407 as coming from the proxy, so it
  re-sends the reque…
severity: high
cvss: 8.2
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-200
vendor: Eclipse Foundation
product: 'org.eclipse.jetty:jetty-client'
affected:
  - 'org.eclipse.jetty:jetty-client >= 12.1.0 <= 12.1.12'
  - 'org.eclipse.jetty:jetty-client >= 12.0.0 <= 12.0.38'
  - 'org.eclipse.jetty:jetty-client >= 11.0.0 <= 11.0.32'
  - 'org.eclipse.jetty:jetty-client >= 10.0.0 <= 10.0.32'
  - 'org.eclipse.jetty:jetty-client >= 9.4.0 <= 9.4.64'
published: '2026-10-15'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T09:17:18.573'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77711'
references:
  - url: >-
      https://github.com/jetty/jetty.project/security/advisories/GHSA-r2c5-3p8g-wpvw
    label: emo@eclipse.org
  - url: 'https://gitlab.eclipse.org/security/cve-assignment/-/work_items/238'
    label: emo@eclipse.org
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-10-15T08:58:33.093Z'
---

## Overview

When Jetty's `HttpClient` make a request to a server through a forward proxy, the server may reply with a 407 (Proxy Authentication Required).



The client mistakenly interprets the 407 as coming from the proxy, so it re-sends the request with the `Proxy-Authentication` header, which arrives to the server, that now has access to the proxy credentials.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.