CVE-2026-118030
Keycloak-services: keycloak-services: hotp race condition allows single otp code reuse across concurrent logins
- State
- Published
- Severity
- 4.2 Medium
- Published
- Oct 29, 2026
- Updated
- Oct 29, 2026
- Reserved
- Oct 27, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.2 Medium | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N | redhat |
Weaknesses
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Products
| Product | Versions |
|---|---|
Red Hat Build of KeycloakRed Hat | |
Red Hat Build of KeycloakRed Hat | |
Red Hat Single Sign-On 7Red Hat |
References
- https://access.redhat.com/security/cve/CVE-2026-118030vdb-entry
- RHBZ#2562005issue-tracking
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