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Fencer Vulns
low 3.7

CVE-2026-107284 json

AsyncHttpClient: WebSocket handshake continues after a failed Sec-WebSocket-Accept check

published 2026-10-07 32 d ago modified 2026-10-08 31 d ago also EUVD-2026-94644

cvss
3.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

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.

Patch / fix

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-107284 updated cvss 3.7

org.asynchttpclient/async-http-client: async-http-client: Processing of unverified WebSocket frames via improper handshake validation

  • Red Hat Fuse 7 async-http-client 2.0.40
    affected: workaround, no fix planned “Out of support scope”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
31 d ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected products

  • AsyncHttpClient async-http-client

Classification

Weakness
  • CWE-345 Insufficient Verification of Data Authenticity
  • CWE-670 Always-Incorrect Control Flow Implementation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.