Review reviewCritical

CVE-2026-28369

Red Hat Red Hat JBoss Enterprise Application Platform 8.1, Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8, Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9

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.

CVSS
9.1
EPSS
0.68%
48.7% percentile
CISA KEV
Not listed
Published
2026.03.28
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.68%
Technical severityCVSS 9.1

Vulnerability 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 product and versions

Product
Red Hat Red Hat JBoss Enterprise Application Platform 8.1, Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8, Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
Affected versions
4.0, 8.0, 7.0.0, 8.0.0, 7.0, 9.0
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Red Hat Red Hat JBoss Enterprise Application Platform 8.1, Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8, Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE
CWE-444