CVE-2026-857205.9MediumCWE-319

CVE-2026-85720: AsyncHttpClient: Origin credentials sent to the proxy on the plaintext CONNECT request

AsyncHttpClient · async-http-client

Affected: AsyncHttpClient async-http-client · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.3%probability of exploitation in the next 30 days

18th percentile

050100

Higher than 18% of scored CVEs

5.9MediumCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

AsyncHttpClient · async-http-client>= 2.0.0, < 2.16.1; >= 3.0.0, < 3.0.12

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Cleartext Transmission of Sensitive Information · Cryptography
Vendor: AsyncHttpClient
Published: September 2026
Band: Unlikely (under 1%), September 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-85720 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.