{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-9798", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-05-28T03:51:03.615Z", "datePublished": "2026-05-28T04:37:09.472Z", "dateUpdated": "2026-05-28T04:37:09.472Z"}, "containers": {"cna": {"title": "Keycloak: keycloak: brute-force protection bypass in ciba flow", "metrics": [{"other": {"content": {"value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "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": [{"vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rhbk/keycloak-rhel9", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:build_keycloak:"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-9798", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482470", "name": "RHBZ#2482470", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-05-28T03:53:01.734Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-305", "description": "Authentication Bypass by Primary Weakness", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-305: Authentication Bypass by Primary Weakness", "workarounds": [{"lang": "en", "value": "To mitigate this issue, ensure that Client-Initiated Backchannel Authentication (CIBA) is not enabled in Keycloak realms unless explicitly required. If CIBA is enabled, consider disabling it to prevent the bypass of brute-force protection mechanisms. Consult Keycloak documentation for instructions on managing CIBA configuration."}], "timeline": [{"lang": "en", "time": "2026-05-28T03:49:51.972Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-05-28T03:53:01.734Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Evan Hendra (Independent Security Researcher) for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-05-28T04:37:09.472Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-9798", "lastModified": "2026-05-28T06:16:29.330", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "secalert@redhat.com", "type": "Primary"}]}, "published": "2026-05-28T06:16:29.330", "references": [{"source": "secalert@redhat.com", "url": "https://access.redhat.com/security/cve/CVE-2026-9798"}, {"source": "secalert@redhat.com", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482470"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-305"}], "source": "secalert@redhat.com", "type": "Primary"}]}

{"acknowledgement": "Red Hat would like to thank Evan Hendra (Independent Security Researcher) for reporting this issue.", "bugzilla": {"description": "keycloak: Keycloak: Brute-force protection bypass in CIBA flow", "id": "2482470", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482470"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N", "status": "draft"}, "cwe": "CWE-305", "details": ["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."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, ensure that Client-Initiated Backchannel Authentication (CIBA) is not enabled in Keycloak realms unless explicitly required. If CIBA is enabled, consider disabling it to prevent the bypass of brute-force protection mechanisms. Consult Keycloak documentation for instructions on managing CIBA configuration."}, "name": "CVE-2026-9798", "package_state": [{"cpe": "cpe:/a:redhat:build_keycloak:", "fix_state": "Affected", "package_name": "rhbk/keycloak-rhel9", "product_name": "Red Hat Build of Keycloak"}], "public_date": "2026-05-28T03:53:01Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-9798\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-9798"], "statement": "This flaw in Keycloak's Client-Initiated Backchannel Authentication (CIBA) flow is rated as Low impact. The vulnerability allows bypassing brute-force protection when a user account is locked, but only if CIBA is explicitly enabled and configured (non-default), and the user approves the authentication request on their device. This significantly limits the attack surface in typical Red Hat deployments where CIBA is not enabled by default.", "threat_severity": "Moderate"}