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.
CVE-2026-28367
CVSS base score
8.7 (v3.1)
Severity
HIGH
Attack vector
Network
Weakness
CWE-444
Last modified
October 30, 2026
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
Affected products
redhat build of apache camel - hawtio
redhat build of apache camel for spring boot
redhat data grid
redhat fuse
redhat jboss enterprise application platform
redhat jboss enterprise application platform expansion pack
redhat process automation
redhat single sign-on
redhat undertow
References
- access.redhat.com
- access.redhat.com
- access.redhat.com Vendor Advisory
- bugzilla.redhat.com Issue Tracking, Vendor Advisory