Keycloak-services: keycloak-services: ciba confidential-only contract not enforced for public clients

Summary

CVECVE-2026-109082
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-12 07:16:36 UTC
Updated2026-10-12 08:17:19 UTC
DescriptionA flaw was found in the Client-Initiated Backchannel Authentication CIBA implementation within the keycloak-services component of Keycloak. This component handles advanced authentication flows where a client initiates a login on behalf of a user. The issue occurs because Keycloak fails to verify that a client is authorized to use the CIBA flow, allowing public clients to bypass security requirements. An attacker could use this flaw to trick a user into approving a login request, eventually gaining full access to the users account without needing a client secret.

Risk And Classification

Primary CVSS: v3.1 6.8 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Problem Types: CWE-287 | CWE-287 Improper Authentication


VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
3.1CNACVSS6.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Red Hat Red Hat Build Of Keycloak Not specified Not specified
CNA Red Hat Red Hat Build Of Keycloak Not specified Not specified
CNA Red Hat Red Hat Single Sign-On 7 Not specified Not specified

References

ReferenceSourceLinkTags
bugzilla.redhat.com/show_bug.cgi [email protected] bugzilla.redhat.com
access.redhat.com/security/cve/CVE-2026-109082 [email protected] access.redhat.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Red Hat would like to thank MZOUGHI Mohamed Amine (zerOiQ) for reporting this issue. (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-10-09T18:42:43.000ZReported to Red Hat.
CNA2026-10-09T18:42:43.000ZMade public.

Workarounds

CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report