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Vulnerability record/PUBLISHED/Published Oct 29, 2026 06:22:11 UTC

CVE-2026-118030

A 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.

Base score4.2/ 10
SeverityMediumCVSS 3.1

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes
Base severityMedium
Attack vectorNetworkAV
Attack complexityHighAC
Privileges requiredLowPR
User interactionNoneUI
ScopeUnchangedS
Confidentiality impactLowC
Integrity impactLowI
Availability impactNoneA
CVSS vector stringCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering Authorityredhat
Last updatedOct 29, 2026 06:22:11 UTC
PublishedOct 29, 2026 06:22:11 UTC
ReservedOct 27, 2026 14:17:43 UTC

Credits

  • Red Hat would like to thank Muhannad Alsaif (xNadByte) for reporting this issue.