๐Ÿ” CVE Alert

CVE-2026-55688

MEDIUM 4.0

AsyncHttpClient: Cookie stored for an unrelated domain (cookie tossing) via ThreadSafeCookieStore

CVSS Score
4.0
EPSS Score
0.2%
EPSS Percentile
8th

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. In versions from 2.0.0 prior to 2.16.0 and from 3.0.0.Beta1 prior to 3.0.11, ThreadSafeCookieStore stored a cookie under the value of its Domain attribute without verifying that the responding host is allowed to set a cookie for that domain, leading to a cookie tossing / cookie injection issue. A host the client connects to can therefore plant a cookie scoped to an unrelated domain, and the client will then send that cookie on later requests to that domain. Applications that use a single AsyncHttpClient instance - and thus the default, shared CookieStore - to reach both an attacker-influenced host and a trusted host are impacted. This issue has been fixed in versions 2.16.0 and 3.0.11.

CWE CWE-1275
Vendor asynchttpclient
Product async-http-client
Published Jul 1, 2026
Last Updated Jul 2, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
None

Affected Versions

AsyncHttpClient / async-http-client
>= 2.0.0, < 2.16.0 >= 3.0.0.Beta1, < 3.0.11

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-m452-q8c9-rg2f github.com: https://github.com/AsyncHttpClient/async-http-client/pull/2196