---
id: CVE-2026-28369
title: A flaw was found in Undertow
summary: >-
  A flaw was found in Undertow. When Undertow receives an HTTP request where the
  first header line starts with one or more spaces, it incorrectly processes the
  request by stripping these leading spaces. This behavior, which violates HTTP
  s…
severity: high
cvss: 8.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N'
cwe:
  - CWE-444
vendor: redhat
product: build_of_apache_camel_-_hawtio
affected:
  - build_of_apache_camel_-_hawtio = 4.0
  - build_of_apache_camel_for_spring_boot = 4.0
  - data_grid = 8.0
  - fuse = 7.0.0
  - jboss_enterprise_application_platform = 7.0.0
  - jboss_enterprise_application_platform = 8.0.0
  - jboss_enterprise_application_platform_expansion_pack
  - process_automation = 7.0
  - single_sign-on = 7.0
  - undertow
  - enterprise_linux = 9.0
published: '2026-03-27'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T14:17:15.593'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28369'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:25125'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:25126'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-28369'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2443262'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28369.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-28369'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28369'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-03-28T03:55:51.631071Z'
epss: 0.00886
epssPercentile: 0.57483
ingestedAt: '2026-07-22T06:58:46.576Z'
patched:
  - jboss_eap_8_1_for_rhel 8
  - jboss_eap_8_1_for_rhel 9
  - jboss_enterprise_application_platform 8.1.7.GA
---

## Overview

A flaw was found in Undertow. When Undertow receives an HTTP request where the first header line starts with one or more spaces, it incorrectly processes the request by stripping these leading spaces. This behavior, which violates HTTP standards, can be exploited by a remote attacker to perform request smuggling. Request smuggling allows an attacker to bypass security mechanisms, access restricted information, or manipulate web caches, potentially leading to unauthorized actions or data exposure.

## Affected

- `build_of_apache_camel_-_hawtio = 4.0`
- `build_of_apache_camel_for_spring_boot = 4.0`
- `data_grid = 8.0`
- `fuse = 7.0.0`
- `jboss_enterprise_application_platform = 7.0.0`
- `jboss_enterprise_application_platform = 8.0.0`
- `jboss_enterprise_application_platform_expansion_pack`
- `process_automation = 7.0`
- `single_sign-on = 7.0`
- `undertow`
- `enterprise_linux = 9.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:25125** · Red Hat · fixed in: Red Hat JBoss EAP 8.1 for RHEL 8, Red Hat JBoss EAP 8.1 for RHEL 9 · released 2026-06-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:25125)
- **RHSA-2026:25126** · Red Hat · fixed in: Red Hat JBoss Enterprise Application Platform 8.1.7.GA · released 2026-06-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:25126)
- **Red Hat VEX** · Important · affected: Red Hat build of Apache Camel for Spring Boot 4, Red Hat Data Grid 8, Red Hat Enterprise Linux 9, Red Hat Fuse 7, Red Hat JBoss Enterprise Application Platform 7, Red Hat JBoss Enterprise Application Platform 8, … · no fix planned: Red Hat Data Grid 8, Red Hat Fuse 7, Red Hat JBoss Enterprise Application Platform 7, Red Hat Process Automation 7, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28369.json)