CVE-2026-9798
Low
No strong exploitation signal.
CVSS base
4.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS — probability of exploitation (30 days)
0.3%
28.4th percentile
CISA KEV
Not listed
Weakness / dates
CWE-305
Published 2026-05-28 · modified 2026-08-20
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | R | Required |
| Scope | U | Unchanged |
| Confidentiality | L | Low |
| Integrity | N | None |
| Availability | N | None |
Timeline
- 2026-05-28 — Published (NVD)
- 2026-08-20 — Last modified (NVD)
Description
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.
Affected
References
- https://access.redhat.com/errata/RHSA-2026:50846
- https://access.redhat.com/errata/RHSA-2026:50847
- https://access.redhat.com/errata/RHSA-2026:50848
- https://access.redhat.com/errata/RHSA-2026:50849
- https://access.redhat.com/security/cve/CVE-2026-9798
- https://bugzilla.redhat.com/show_bug.cgi?id=2482470