CVE-2026-107280
Description
A flaw was found in AsyncHttpClient. The cookie storage mechanism fails to reject public domain suffixes (such as .co.uk) when validating cookie domain attributes. A remote attacker controlling a website under a shared public suffix can set cookies for the entire suffix, causing the client to transmit them to unrelated websites. This issue allows an attacker to inject or overwrite session cookies across different domains, compromising session integrity.
Statement
A flaw was found in the AsyncHttpClient (AHC) Java library, which Red Hat JBoss Fuse 7 ships as a Maven dependency. The ThreadSafeCookieStore cookie store validates cookie Domain attributes using only RFC 6265 domain matching and does not reject public suffixes. A remote attacker who controls a website beneath a shared public suffix such as co.uk can therefore set a cookie for the entire suffix, and the shared cookie store then sends that cookie to unrelated hosts under the same suffix, for example from attacker.co.uk to bank.co.uk. This allows the attacker to inject or overwrite session-relevant cookie values across origins, compromising session integrity through session fixation or by replacing cookies set by the target site. Red Hat rates this flaw as MODERATE impact (CVSS 5.3), consistent with the upstream MODERATE rating; exploitation requires the attacker to operate a site under the same public suffix as the target host, which is trivially obtainable for suffixes such as co.uk or com.au. The only affected Red Hat product is Red Hat JBoss Fuse 7, where async-http-client is delivered through the fuse-7-els-2 update stream; that stream is not in full support scope, so the affect has been resolved as Out of Support Scope and no Red Hat fix is currently planned for it.
Mitigation
Upstream fixed this issue in AsyncHttpClient 3.0.13 on the 3.x line and from 2.16.1 on the 2.x line; applications can upgrade the org.asynchttpclient:async-http-client dependency accordingly. As workarounds, the upstream advisory recommends not sharing one CookieStore across origins that are not mutually trusted, or supplying a CookieStore implementation that rejects Domain attribute values which are public suffixes. No updated Red Hat package is planned because the only affected Red Hat stream, fuse-7-els-2, is out of support scope.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | Low | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
An attacker can access any functionality that is inadvertently accessible to the source.
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