CVE-2026-9798
Keycloak: keycloak: brute-force protection bypass in ciba flow
CVSS Score
4.3
EPSS Score
0.1%
EPSS Percentile
17th
A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.
| CWE | CWE-305 |
| Vendor | red hat |
| Product | red hat build of keycloak |
| Published | May 28, 2026 |
| Last Updated | May 29, 2026 |
Stay Ahead of the Next One
Get instant alerts for red hat red hat build of keycloak
Be the first to know when new medium vulnerabilities affecting red hat red hat build of keycloak are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
Red Hat / Red Hat Build of Keycloak
All versions affected References
Credits
Red Hat would like to thank Evan Hendra (Independent Security Researcher) for reporting this issue.