CVE-2026-107284 AsyncHttpClient: WebSocket handshake continues after a failed Sec-WebSocket-Accept check
Attackers can bypass WebSocket handshake validation to receive frames from unverified peers, potentially exposing data or enabling further attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-107284?
CVE-2026-107284 is a low-severity vulnerability in AsyncHttpClient async-http-client, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. Prior to 3.0.12 and 2.16.1, WebSocketHandler.upgrade aborts a handshake whose Sec-WebSocket-Accept value is missing or invalid but continues into pipeline installation and onOpen delivery. Frames coalesced with the invalid 101 response can be decoded and delivered from a peer that did not prove the handshake, although the request future fails and the channel closes. This issue is fixed in versions 3.0.12 and 2.16.1.
Which versions are affected by CVE-2026-107284?
How do I fix CVE-2026-107284?
No fix has been published for CVE-2026-107284 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-107284 being exploited?
There is no known exploitation of CVE-2026-107284 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-107284, GHSA-rwhr-j9rv-85f8, UBUNTU-CVE-2026-107284.