CVE-2026-28368 Undertow: undertow: request smuggling via inconsistent header parsing
Remote attackers can exploit inconsistent header parsing in Undertow to perform request smuggling, bypassing security controls and accessing unauthorized resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-28368?
CVE-2026-28368 is a high-severity vulnerability in Redhat Enterprise Linux, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-444
Which versions are affected by CVE-2026-28368?
2 open source packages ship an affected version, including io.undertow:undertow-parent. It affects 10 products.
| Package | Affected | Fixed in |
|---|---|---|
io.undertow:undertow-parent Maven | All versions to 2.3.23.Final | None |
io.undertow:undertow-parent Maven | All versions to 2.3.23.Final | None |
Products include Redhat Build of Apache Camel - Hawtio, Redhat Build of Apache Camel for Spring Boot, Redhat Data Grid, Redhat Enterprise Linux, Redhat Fuse, Redhat Jboss Enterprise Application Platform and 4 more.
How do I fix CVE-2026-28368?
Apply the vendor's patch.
Is CVE-2026-28368 being exploited?
There is no known exploitation of CVE-2026-28368 in the wild and no public exploit code.
Other vulnerabilities in Redhat Enterprise Linux
Sources
Also known as DEBIAN-CVE-2026-28368, GHSA-8v4x-mgvp-p658, UBUNTU-CVE-2026-28368.