Bug 2443260 (CVE-2026-28367)

Summary: CVE-2026-28367 undertow: Undertow: Request smuggling via `\r\r\r` as a header block terminator
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: abrianik, aschwart, asoldano, bbaranow, bmaxwell, boliveir, brian.stansberry, bstansbe, darran.lofthouse, dhanak, dlofthou, dosoudil, drosa, fjuma, fmariani, ggrzybek, gmalinko, ibek, istudens, ivassile, iweiss, janstey, jrokos, kverlaen, mnovotny, mosmerov, mposolda, msvehla, nwallace, parichar, pberan, pdelbell, pesilva, pjindal, pmackay, rmartinc, rstancel, rstepani, sausingh, security-response-team, smaestri, ssilvert, sthorger, tasato, tcunning, thjenkin, tom.jenkinson, vdosoudi, vmuzikar, yfang
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
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.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-02-27 04:44:46 UTC
Undertow allows `\r\r\r` as a header block terminator. This can be used for request smuggling with proxy servers that forwards this byte sequence, including older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer.

Comment 2 errata-xmlrpc 2026-06-10 20:25:05 UTC
This issue has been addressed in the following products:

  Red Hat JBoss Enterprise Application Platform 8.1

Via RHSA-2026:25126 https://access.redhat.com/errata/RHSA-2026:25126

Comment 3 errata-xmlrpc 2026-06-10 20:27:07 UTC
This issue has been addressed in the following products:

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

Via RHSA-2026:25125 https://access.redhat.com/errata/RHSA-2026:25125