7.5High

CVE-2026-85719

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 2.1.0 until 2.16.1 and 3.0.12, requests using an authenticated SOCKS proxy can expose the proxy's credentials to the origin because NettyRequestFactory and NettyRequestSender attach Proxy-Authorization without confirming that the request is being sent to an HTTP proxy. With preemptive proxy authentication, the header is attached to a plaintext HTTP request, exposing credentials such as directly reversible Basic credentials to the origin. With the default non-preemptive flow, a hostile origin can return a 407 response and ProxyUnauthorized407Interceptor sends the proxy credentials through the existing SOCKS tunnel, including NTLM, Kerberos, and SPNEGO credentials. Releases before 2.1.0 lack SOCKS proxy support. This issue is fixed in versions 2.16.1 and 3.0.12.

What this means for your business

  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
7.5 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-319
Assigned by
security-advisories@github.com

Dates

Published
2026-09-17
Last modified
2026-09-18
Sources
NVD

References