Description
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.
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
References4
- access.redhat.com/security/cve/CVE-2026-28367 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2443260 Issue TrackingVendor Advisory
- access.redhat.com/errata/RHSA-2026:25125
- access.redhat.com/errata/RHSA-2026:25126
Metrics
- CVSS 3.1
-
9.1
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 1% percentile: 54 · as of 12 November 2026
- CWE
- CWE-444
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.