AsyncHttpClient CookieStore Silently Overrides Caller's Explicit Cookie Header via setHeader (Bypass of CVE-2024-53990 Fix)

published 2026-10-07 32 d ago modified 2026-10-08 31 d ago also GHSA-2jwh-9rmr-j4xf , EUVD-2026-94589

cvss: 6.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 2.1.0 until 3.0.14, the enabled-by-default cookie store replaces a Cookie header explicitly supplied through setHeader or addHeader whenever the store contributes any cookie for the origin. In a shared client, stored cookies originating from one user can replace a different user's request cookie, causing the request to execute under the wrong session. This bypasses the earlier CVE-2024-53990 remediation, which covered cookies supplied through addCookie but not a directly supplied header. This issue is fixed in version 3.0.14.

Patch / fix

fixed in 1 links 2

maven org.asynchttpclient:async-http-client 3.0.14

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-2026-107228 updated 2026-11-04 cvss 6.8

org.asynchttpclient/async-http-client: AsyncHttpClient: Session hijacking via improper cookie header handling

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: total
Assessed: 31 d ago (2026-10-08)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.8	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
GitHub	3.1	6.8	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
maven	org.asynchttpclient:async-http-client	>=3.0.0, <3.0.14 >=2.1.0, <=2.16.1	3.0.14

Affected products

AsyncHttpClient async-http-client

Classification

Weakness

CWE-287 Improper Authentication

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.

Summary