CVE-2026-16103

A flaw was found in the keycloak-services component of Keycloak. This issue is an incomplete fix for CVE-2026-9798, where brute-force protection checks were added to the Client-Initiated Backchannel Authentication (CIBA) initiation handler but were omitted from the token redemption handler. This allows an attacker with valid client credentials to obtain access and refresh tokens for a user account that has been locked due to brute-force protection, provided the authentication request was started before the lockout occurred and was approved by the user.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/security/cve/CVE-2026-16103
https://bugzilla.redhat.com/show_bug.cgi?id=2501736

Configurations

No configuration.

History

21 Jul 2026, 15:16

Type	Values Removed	Values Added
CWE		CWE-841

17 Jul 2026, 17:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-17 17:17

Updated : 2026-07-21 15:16

NVD link : CVE-2026-16103

Mitre link : CVE-2026-16103

CVE.ORG link : CVE-2026-16103

JSON object : View

Products Affected

No product.

CWE

CWE-841

Improper Enforcement of Behavioral Workflow

{"id": "CVE-2026-16103", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-16103", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-17T17:01:59.231875Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "secalert@redhat.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 1.4, "exploitabilityScore": 2.8}]}, "affected": [{"source": "secalert@redhat.com", "affectedData": [{"cpes": ["cpe:/a:redhat:build_keycloak:"], "vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:"], "vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "packageName": "rhbk-keycloak-rhel9/rhbk-keycloak-rhel9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:"], "vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "packageName": "rhbk-openshift-rhel9/rhbk-openshift-rhel9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jboss_data_grid:8"], "vendor": "Red Hat", "product": "Red Hat Data Grid 8", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:jbosseapxp"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:red_hat_single_sign_on:7"], "vendor": "Red Hat", "product": "Red Hat Single Sign-On 7", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}]}], "published": "2026-07-17T17:17:14.263", "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-16103", "source": "secalert@redhat.com"}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2501736", "source": "secalert@redhat.com"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-841"}]}], "descriptions": [{"lang": "en", "value": "A flaw was found in the keycloak-services component of Keycloak. This issue is an incomplete fix for CVE-2026-9798, where brute-force protection checks were added to the Client-Initiated Backchannel Authentication (CIBA) initiation handler but were omitted from the token redemption handler. This allows an attacker with valid client credentials to obtain access and refresh tokens for a user account that has been locked due to brute-force protection, provided the authentication request was started before the lockout occurred and was approved by the user."}], "lastModified": "2026-07-21T15:16:31.950", "sourceIdentifier": "secalert@redhat.com"}