Vulnerability Report

CVE-2026-28367

Title: Undertow Request Smuggling via `\r\r\r` as header block terminator

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2026-28367.

CWE Category CWE-444
Published Date Mar 27, 2026
Modified Date Oct 14, 2026
Exploit Status Not Found
Score 8.7 CVSS v3.1
Exploit Probability (EPSS)
0.89%

Vulnerability Summary

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 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.

Impacted Vendors

B
broadcom 1
P
pivotal 1
F
fuse 1
M
miklos_szeredi 1
R
redhat 9

Reference Links

https://access.redhat.com/security/cve/CVE-2026-28367 https://bugzilla.redhat.com/show_bug.cgi?id=2443260
CVSS v3.1
Source Entity [email protected]
Severity HIGH
8.7
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
CVSS v3.1
Source Entity [email protected]
Severity CRITICAL
9.1
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-28367 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

Affected Stack

No specific products linked.