Keycloak-services: keycloak-services: hotp race condition allows single otp code reuse across concurrent logins

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-118030
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-29 07:16:44 UTC
Updated2026-10-29 07:16:45 UTC
DescriptionA flaw was found in the HOTP authentication mechanism of the keycloak-services component, which provides identity and access management services. The issue occurs because the system validates a one-time password and updates its internal counter in two separate steps without proper locking. An attacker with a users password could exploit this timing gap to use a single one-time code to log in multiple times simultaneously.

Risk And Classification

Primary CVSS: v3.1 4.2 MEDIUM from [email protected]

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

Problem Types: CWE-362 | CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary4.2MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
3.1CNACVSS4.2MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS v3.1 Breakdown

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

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/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-2026-118030 [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 Muhannad Alsaif (xNadByte) for reporting this issue. (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-10-26T13:54:35.000ZReported to Red Hat.
CNA2026-10-26T13:54:35.000ZMade 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