What is CVE-2026-107229?

CVE-2026-107229 is a medium-severity vulnerability in Asynchttpclient Async-Http-Client, classified under Session Fixation. CVSS score: 4.0/10. Published 2026-10-07.

How severe is CVE-2026-107229?

Medium severity. CVSS v3 base score is 4.0 out of 10.

Vulnerability in Asynchttpclient Async-Http-Client

CVE-2026-107229

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 2.16.0 until 3.0.14, ThreadSafeCookieStore incompletely validates cookie Domain attributes. Missing private-section and default public-suffix rules, absent A-label normalization, locale-sensitive lowercasing, public-suffix host-only handling, and numeric or IP host checks allow one origin to store a cookie later sent to another origin. Applications sharing one client across trust domains can therefore receive attacker-injected cookies and may be exposed to session fixation. This issue is fixed in version 3.0.14.

Published 2026-10-07 · last modified 2026-10-08.

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Asynchttpclient Async-Http-Client — versions >= 2.16.0, <= 2.16.1, >= 3.0.11, < 3.0.14

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-107229?: CVE-2026-107229 is a medium-severity vulnerability in Asynchttpclient Async-Http-Client, classified under Session Fixation. CVSS score: 4.0/10. Published 2026-10-07.
How severe is CVE-2026-107229?: Medium severity. CVSS v3 base score is 4.0 out of 10.