Undertow Header Smuggling via Header Name Misparse
CVE-2026-28368 Published on March 27, 2026

Undertow: undertow: request smuggling via inconsistent header parsing
A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.

NVD

Vulnerability Analysis

CVE-2026-28368 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
NONE

Timeline

Reported to Red Hat.

Made public.

Weakness Type

What is a HTTP Request Smuggling Vulnerability?

When malformed or abnormal HTTP requests are interpreted by one or more entities in the data flow between the user and the web server, such as a proxy or firewall, they can be interpreted inconsistently, allowing the attacker to "smuggle" a request to one device without the other device being aware of it.

CVE-2026-28368 has been classified to as a HTTP Request Smuggling vulnerability or weakness.


Products Associated with CVE-2026-28368

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Affected Versions

Red Hat build of Apache Camel for Spring Boot 4: Red Hat build of Apache Camel - HawtIO 4: Red Hat Data Grid 8: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Fuse 7: Red Hat JBoss Enterprise Application Platform 7: Red Hat JBoss Enterprise Application Platform 8: Red Hat JBoss Enterprise Application Platform 8: Red Hat JBoss Enterprise Application Platform 8: Red Hat JBoss Enterprise Application Platform Expansion Pack: Red Hat JBoss Enterprise Application Platform Expansion Pack: Red Hat JBoss Enterprise Application Platform Expansion Pack: Red Hat Process Automation 7: Red Hat Single Sign-On 7: