CVE-2026-55688

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

At a glance

Severity
MEDIUM 4.0
EPSS
EPSS 0.33 % · percentile 26 (2026-10-28)
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Awaiting Analysis

Description

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.

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 4.0CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:NGitHub_M
CVSS 3.1MEDIUM 4.0CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:NNVD · security-advisories@github.com (Secondary)

Weaknesses (CWE)

Advisories

European references

Affected products

ProductVersions
AsyncHttpClient · async-http-clientaffected >= 2.0.0, < 2.16.0 ; affected >= 3.0.0.Beta1, < 3.0.11

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD