Keycloak: keycloak: brute-force protection bypass in ciba flow (Red Hat Red Hat build of Keycloak 26.4)

CVE-2026-9798
MEDIUM 4.3

At a glance

Source
NVD
EPSS
EPSS 0.38 % · percentile 32 ()
State
PUBLISHED
Published
Updated
Assigner
redhat
NVD status
Modified

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.

Weaknesses (CWE)

  • CWE-305 — Authentication Bypass by Primary Weakness

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 4.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:Nredhat
CVSS 3.1MEDIUM 4.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:NNVD · secalert@redhat.com (Secondary)

Advisories

European references

Affected configurations (NVD CPE)

Affected products

ProductVersions
Red Hat · Red Hat build of Keycloak 26.4unaffected 26.4.14-1 < *
Red Hat · Red Hat build of Keycloak 26.4unaffected 26.4-22 < *
Red Hat · Red Hat build of Keycloak 26.4unaffected 26.4-22 < *
Red Hat · Red Hat build of Keycloak 26.4.14
Red Hat · Red Hat build of Keycloak 26.6unaffected 26.6.5-1 < *
Red Hat · Red Hat build of Keycloak 26.6unaffected 26.6-11 < *
Red Hat · Red Hat build of Keycloak 26.6unaffected 26.6-11 < *
Red Hat · Red Hat build of Keycloak 26.6.5

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD