---
id: CVE-2026-85720
title: >-
  The AsyncHttpClient (AHC) library allows Java applications to easily execute
  HTTP requests and asynchronously process HTTP responses
summary: >-
  The AsyncHttpClient (AHC) library allows Java applications to easily execute
  HTTP requests and asynchronously process HTTP responses. From 2.0.0 until
  2.16.1 and 3.0.12, a request using an HTTP proxy to reach an HTTPS origin can
  expose p…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-319
  - CWE-522
vendor: AsyncHttpClient
product: async-http-client
affected:
  - 'async-http-client >= 2.0.0, < 2.16.1'
  - 'async-http-client >= 3.0.0, < 3.0.12'
patched:
  - 'org.asynchttpclient:async-http-client 3.0.12'
  - 'org.asynchttpclient:async-http-client 2.16.1'
published: '2026-09-17'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:16:28.120'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-85720'
references:
  - url: >-
      https://github.com/AsyncHttpClient/async-http-client/commit/9dba5ac988b7e750551f59b2eab550b60ac8a0d6
    label: security-advisories@github.com
  - url: >-
      https://github.com/AsyncHttpClient/async-http-client/commit/d07dbc79f5cf378f63c246f6101d7579ace55acc
    label: security-advisories@github.com
  - url: 'https://github.com/AsyncHttpClient/async-http-client/pull/2234'
    label: security-advisories@github.com
  - url: >-
      https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-xr57-gcx8-52hf
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-xr57-gcx8-52hf'
tags:
  - nvd
  - cve.org
  - ghsa
  - maven
epss: 0.00265
epssPercentile: 0.16416
aliases:
  - GHSA-xr57-gcx8-52hf
ecosystem: maven
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-21T20:52:13.029744Z'
ingestedAt: '2026-09-17T16:21:47.906Z'
---

## Overview

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 2.0.0 until 2.16.1 and 3.0.12, a request using an HTTP proxy to reach an HTTPS origin can expose preemptive origin credentials because NettyRequestFactory and NettyRequestSender.sendRequestWithNewChannel attach Authorization to the plaintext CONNECT request before the TLS tunnel exists. Basic or Digest credentials and per-connection NTLM, Kerberos, or SPNEGO tokens intended for the origin are therefore visible to the proxy and to observers on the client-to-proxy hop. The tunneled request still receives origin Authorization after the tunnel is established, while Proxy-Authorization remains on CONNECT for its intended proxy recipient. This issue is fixed in versions 2.16.1 and 3.0.12.

## Remediation

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

## Package advisory (CVE-2026-85720)

Affected packages:

- `org.asynchttpclient:async-http-client >= 3.0.0, <= 3.0.11`
- `org.asynchttpclient:async-http-client >= 2.0.0, <= 2.16.0`

Patched in:

- `org.asynchttpclient:async-http-client 3.0.12`
- `org.asynchttpclient:async-http-client 2.16.1`

Source: https://github.com/advisories/GHSA-xr57-gcx8-52hf