Undertow: undertow: request smuggling via malformed http request headers
Summary
| CVE | CVE-2026-28369 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-27 17:16:28 UTC |
| Updated | 2026-03-31 18:08:21 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 9.1 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS: 0.001120000 probability, percentile 0.298240000 (date 2026-04-01)
Problem Types: CWE-444 | CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| 3.1 | [email protected] | Secondary | 8.7 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N |
| 3.1 | CNA | CVSS | 8.7 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Redhat | Build Of Apache Camel - Hawtio | 4.0 | All | All | All |
| Application | Redhat | Build Of Apache Camel For Spring Boot | 4.0 | All | All | All |
| Application | Redhat | Data Grid | 8.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 9.0 | All | All | All |
| Application | Redhat | Fuse | 7.0.0 | All | All | All |
| Application | Redhat | Jboss Enterprise Application Platform | 7.0.0 | All | All | All |
| Application | Redhat | Jboss Enterprise Application Platform | 8.0.0 | All | All | All |
| Application | Redhat | Jboss Enterprise Application Platform Expansion Pack | - | All | All | All |
| Application | Redhat | Process Automation | 7.0 | All | All | All |
| Application | Redhat | Single Sign-on | 7.0 | All | All | All |
| Application | Redhat | Undertow | - | All | All | All |
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-28369 | [email protected] | access.redhat.com | Vendor Advisory |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | Issue Tracking, Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-02-27T04:39:59.064Z | Reported to Red Hat. |
| CNA | 2025-08-27T00:00:00.000Z | Made public. |
There are currently no legacy QID mappings associated with this CVE.