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.
CVE-2026-118030
CVSS base score
4.2 (v3.1)
Severity
MEDIUM
Attack vector
Network
Weakness
CWE-362
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N