CVE-2026-85720

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 83% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
5.9
EG Score
5.9(medium)
EG Risk
31(Track)
EG Risk 31/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity59% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
17%
KEV
Not listed

Published

September 17, 2026

Last Modified

September 17, 2026

Advisory Details (4)

Auto-updated Sep 17, 2026
Patch available. Sources: github, github_pr, github_commit.
github_commit Patch Available

commit d07dbc79f5cf (AsyncHttpClient/async-http-client)

Patch available: AsyncHttpClient/async-http-client async-http-client-project-3.0.12 (contains commit d07dbc79f5cf)

https://github.com/AsyncHttpClient/async-http-client/commit/d07dbc79f5cf378f63c246f6101d7579ace55acc
github_commit Patch Available

commit 9dba5ac988b7 (AsyncHttpClient/async-http-client)

Patch available: AsyncHttpClient/async-http-client async-http-client-project-2.16.1 (contains commit 9dba5ac988b7)

https://github.com/AsyncHttpClient/async-http-client/commit/9dba5ac988b7e750551f59b2eab550b60ac8a0d6
github_pr Patch Available

skip origin Authorization on CONNECT proxy request

Patch available: AsyncHttpClient/async-http-client async-http-client-project-3.0.12 (PR #2234 merged 2026-07-04)

https://github.com/AsyncHttpClient/async-http-client/pull/2234
github Patch Available

Origin credentials sent to the proxy on the plaintext CONNECT request · Advisory · AsyncHttpClient/async-http-client · GitHub

Affected: 3.0.12 on the 3.x line and in 2.16.1 on the 2.x line. The origin Basic or Digest

https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-xr57-gcx8-52hf

Vendor Advisories for CVE-2026-85720(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFixed inDependents
org.asynchttpclient:async-http-client3.0.0 ... 3.0.9 (12 versions)3.0.12—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 5× in last 7d / 5× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 18:13 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 17:56 UTCEG score recompute
  4. 2026-09-17 16:20 UTCEG score recompute
  5. 2026-09-17 16:19 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-85720?
CVE-2026-85720 is a medium vulnerability published on September 17, 2026. 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…
When was CVE-2026-85720 disclosed?
CVE-2026-85720 was first published in the National Vulnerability Database on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-85720 actively exploited?
CVE-2026-85720 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 82.8% of all scored CVEs.
What is the CVSS score of CVE-2026-85720?
CVE-2026-85720 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-85720?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-85720, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-85720

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