Keycloak-services: keycloak-services: hotp race condition allows single otp code reuse across concurrent logins (Red Hat Red Hat Build of Keycloak)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.16 % · percentile 5 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Awaiting Analysis
Description
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.
Weaknesses (CWE)
- CWE-362 — Concurrent Execution using Shared Resource with Improper Synchronization
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 4.2 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N | redhat |
| CVSS 3.1 | MEDIUM 4.2 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N | NVD · secalert@redhat.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-112640
- GCVE · GCVE-0-2026-118030
Affected products
| Product | Versions |
|---|---|
| Red Hat · Red Hat Build of Keycloak | |
| Red Hat · Red Hat Build of Keycloak | |
| Red Hat · Red Hat Single Sign-On 7 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |