Medium [CVE-2026-55688] Cookie injection allows planting cookies for unrelated domains
This medium-severity Red Hat Linux advisory covers CVE-2026-55688 affecting Red Hat JBoss Enterprise Application Platform Expansion Pack.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Summary
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. The ThreadSafeCookieStore component did not properly verify the domain attribute of cookies, allowing a malicious host to set a cookie for an unrelated domain.
This could lead to a cookie injection issue, impacting applications that use a single AsyncHttpClient instance to connect to both untrusted and trusted hosts. This Moderate impact flaw in the AsyncHttpClient library, affecting Red Hat Enterprise Application Platform, allows a malicious server to inject cookies for unrelated domains.
Is CVE-2026-55688 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-55688 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-55688?
Upgrade to a fixed release named by Red Hat:
- 2.16.0
- 3.0.11
Confirm against the vendor advisory before you patch.
- < 2.0.0
- < 2.16.0
- < 3.0.0.Beta1
- < 3.0.11
- 3.0.0
Official advisory · high-confidence parse· fetched 13 days ago·verify at source
- 2.16.0
- 3.0.11
Official advisory · high-confidence parse· fetched 13 days ago·verify at source
Mitigation checklist
- Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Official advisory · high-confidence parse· fetched 13 days ago·verify at source
Get an email when Red Hat publishes the next one.
See Red Hat's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).
More Red Hat Linux advisories
- CVE-2026-34197Apr 7, 2026RCE via crafted discovery URI in Jolokia JMX-HTTP bridge
- CVE-2026-119977Oct 31, 2026Arbitrary code execution via predictable upgrade staging paths
- CVE-2026-111497Oct 22, 2026Out-of-Bounds Write in Google Brotli Decoder
- CVE-2026-109619Oct 21, 2026fatal error handling retains stale request state leading to use-after-free
- CVE-2026-109618Oct 21, 2026OOM bailout during request parsing leads to memory corruption and RCE
- CVE-2026-97229Oct 13, 2026integer overflow issue in CI/CD regular expression compiler
iPhone and Android apps · New on the App Store
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.