Summary
AsyncHttpClient: WebSocket proxy credentials sent to the origin server over a CONNECT tunnel
Affected versions
- 3.x: up to and including 3.0.11
- 2.x: up to and including 2.16.0
Workarounds
Do not use proxy authentication together with ws:// requests through an HTTP proxy, or use wss:// instead.
Details
The proxy-auth gate in NettyRequestFactory#newNettyRequest and the sibling branch in requestUri() did not exclude WebSocket URIs, even though the CONNECT-tunnelling check in NettyRequestSender already tunnels ws:// through CONNECT exactly like https://.
Note that 3.0.12 is itself affected by a separate issue, GHSA-rqf5-2wxv-rjf4, where a Digest challenge the client cannot read downgrades to Basic and sends the password in cleartext. Upgrade to 3.0.13 to pick up both fixes.
Impact
When a ws:// request is routed through an HTTP proxy with proxy authentication configured, the client tunnels the connection with an HTTP CONNECT, the same as it does for https://. Once the tunnel is open, the WebSocket upgrade request that follows is sent through the tunnel directly to the origin server, not to the proxy. The proxy-auth gate and the companion request-target selection keyed only on whether the URI was secured, which is false for ws://, so the tunnelled upgrade request incorrectly carried the proxy's Proxy-Authorization header and an absolute-form request target meant for the proxy. Any origin server reached over a proxied ws:// connection, or anyone positioned on the origin side of the wire, could recover the proxy credentials: directly for Basic, or as a replayable and offline-crackable response for Digest.
CVE-2026-107285 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.0.12, 2.16.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Fixed in 3.0.12 on the 3.x line and in 2.16.1 on the 2.x line. The preemptive Proxy-Authorization header and the absolute-form request target are no longer attached to a tunnelled ws:// upgrade; a ws:// request is now treated like wss://.
Frequently Asked Questions
- What is CVE-2026-107285? CVE-2026-107285 is a medium-severity security vulnerability in org.asynchttpclient:async-http-client (maven), affecting versions >= 3.0.0, <= 3.0.11. It is fixed in 3.0.12, 2.16.1.
- How severe is CVE-2026-107285? CVE-2026-107285 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.asynchttpclient:async-http-client are affected by CVE-2026-107285? org.asynchttpclient:async-http-client (maven) versions >= 3.0.0, <= 3.0.11 is affected.
- Is there a fix for CVE-2026-107285? Yes. CVE-2026-107285 is fixed in 3.0.12, 2.16.1. Upgrade to this version or later.
- Is CVE-2026-107285 exploitable, and should I be worried? Whether CVE-2026-107285 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-107285 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-107285?
- Upgrade
org.asynchttpclient:async-http-clientto 3.0.12 or later - Upgrade
org.asynchttpclient:async-http-clientto 2.16.1 or later
- Upgrade