Vulnerability in Red Hat Build Of Keycloak
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.
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (5.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-118030 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
Frequently asked questions
- What is CVE-2026-118030?
- CVE-2026-118030 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 4.2/10. Published 2026-10-29.
- How severe is CVE-2026-118030?
- Medium severity. CVSS v3 base score is 4.2 out of 10.