---
title: "CVE-2026-77711: Jetty HttpClient - Authentication Bypass"
description: "Jetty HttpClient contains a proxy authentication misinterpretation caused by treating server 407 responses as proxy responses, letting attackers gain proxy credentials disclosure, exploit requires use of forward proxy."
url: https://panop.io/threat-heartbeat/CVE-2026-77711/
---

# CVE-2026-77711 Jetty HttpClient - Authentication Bypass

Jetty HttpClient contains a proxy authentication misinterpretation caused by treating server 407 responses as proxy responses, letting attackers gain proxy credentials disclosure, exploit requires use of forward proxy.

CVSS base score 8.2 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-77711)

## Details

Type

Authentication Bypass

Impact

Information Disclosure

CVSS vector

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/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

Published

15 October 2026

Updated

15 October 2026

Weakness

[CWE-200](https://cwe.mitre.org/data/definitions/200.html)

## Vendor fix

Update to the latest version of Jetty HttpClient that correctly handles 407 responses.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-77711](https://nvd.nist.gov/vuln/detail/CVE-2026-77711)
- [https://github.com/jetty/jetty.project/security/advisories/GHSA-r2c5-3p8g-wpvw](https://github.com/jetty/jetty.project/security/advisories/GHSA-r2c5-3p8g-wpvw)
- [https://gitlab.eclipse.org/security/cve-assignment/-/work\_items/238](https://gitlab.eclipse.org/security/cve-assignment/-/work_items/238)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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