Home/CVE/A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\r\r\r` as a header block ter
CVE

CVE-2026-28367

A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\r\r\r` as a header block ter

A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending \r\r\r as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.

HIGH · CVSS 8.7 EPSS 0.00049
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
▤

Affected Products & Versions

9
redhat build of apache camel - hawtioall versions
redhat build of apache camel for spring bootall versions
redhat data gridall versions
redhat fuseall versions
redhat jboss enterprise application platformall versions
redhat jboss enterprise application platform expansion packall versions
redhat process automationall versions
redhat single sign-onall versions
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Maven io.undertow:undertow-parent HIGH
▣

Scoring & Timeline

8.7
HIGH · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD27 Mar 2026 · 05:16 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://access.redhat.com/security/cve/CVE-2026-28367Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2443260Issue TrackingVendor Advisory
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