Vulnerability Description
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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/AsyncHttpClient/async-http-client/commit/9dba5ac988b7e750551f
- https://github.com/AsyncHttpClient/async-http-client/commit/d07dbc79f5cf378f63c2
- https://github.com/AsyncHttpClient/async-http-client/pull/2234
- https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-xr
FAQ
What is CVE-2026-85720?
CVE-2026-85720 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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 ...
How severe is CVE-2026-85720?
CVE-2026-85720 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-85720?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.