{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-4634", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-03-23T08:41:40.650Z", "datePublished": "2026-04-02T12:44:53.424Z", "dateUpdated": "2026-04-03T17:23:00.421Z"}, "containers": {"cna": {"title": "Keycloak: keycloak: denial of service via excessive processing of openid connect scope parameters", "metrics": [{"other": {"content": {"value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhbk/keycloak-operator-bundle", "defaultStatus": "affected", "versions": [{"version": "26.2.15-1", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"]}, {"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhbk/keycloak-rhel9", "defaultStatus": "affected", "versions": [{"version": "26.2-18", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"]}, {"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhbk/keycloak-rhel9-operator", "defaultStatus": "affected", "versions": [{"version": "26.2-18", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"]}, {"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2.15", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected", "packageName": "rhbk/keycloak-rhel9", "cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"]}, {"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhbk/keycloak-operator-bundle", "defaultStatus": "affected", "versions": [{"version": "26.4.11-1", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"]}, {"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhbk/keycloak-rhel9", "defaultStatus": "affected", "versions": [{"version": "26.4-14", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"]}, {"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhbk/keycloak-rhel9-operator", "defaultStatus": "affected", "versions": [{"version": "26.4-14", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"]}, {"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4.11", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected", "packageName": "rhbk/keycloak-rhel9", "cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"]}], "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:6475", "name": "RHSA-2026:6475", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:6476", "name": "RHSA-2026:6476", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:6477", "name": "RHSA-2026:6477", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:6478", "name": "RHSA-2026:6478", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/security/cve/CVE-2026-4634", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450250", "name": "RHBZ#2450250", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-04-02T12:30:00.000Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-1050", "description": "Excessive Platform Resource Consumption within a Loop", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-1050: Excessive Platform Resource Consumption within a Loop", "workarounds": [{"lang": "en", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}], "timeline": [{"lang": "en", "time": "2026-03-23T08:40:02.817Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-04-02T12:30:00.000Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Slvrqn for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-04-02T16:35:02.691Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-04-03T17:22:51.847497Z", "id": "CVE-2026-4634", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-03T17:23:00.421Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-4634", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-03T17:22:51.847497Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-03T17:22:55.273Z"}}], "cna": {"title": "Keycloak: keycloak: denial of service via excessive processing of openid connect scope parameters", "credits": [{"lang": "en", "value": "Red Hat would like to thank Slvrqn for reporting this issue."}], "metrics": [{"other": {"type": "Red Hat severity rating", "content": {"value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/"}}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}], "affected": [{"cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2", "versions": [{"status": "unaffected", "version": "26.2.15-1", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhbk/keycloak-operator-bundle", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2", "versions": [{"status": "unaffected", "version": "26.2-18", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhbk/keycloak-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2", "versions": [{"status": "unaffected", "version": "26.2-18", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhbk/keycloak-rhel9-operator", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:26.2::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.2.15", "packageName": "rhbk/keycloak-rhel9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4", "versions": [{"status": "unaffected", "version": "26.4.11-1", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhbk/keycloak-operator-bundle", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4", "versions": [{"status": "unaffected", "version": "26.4-14", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhbk/keycloak-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4", "versions": [{"status": "unaffected", "version": "26.4-14", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhbk/keycloak-rhel9-operator", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4.11", "packageName": "rhbk/keycloak-rhel9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}], "timeline": [{"lang": "en", "time": "2026-03-23T08:40:02.817Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-04-02T12:30:00.000Z", "value": "Made public."}], "datePublic": "2026-04-02T12:30:00.000Z", "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:6475", "name": "RHSA-2026:6475", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:6476", "name": "RHSA-2026:6476", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:6477", "name": "RHSA-2026:6477", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:6478", "name": "RHSA-2026:6478", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/security/cve/CVE-2026-4634", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450250", "name": "RHBZ#2450250", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "workarounds": [{"lang": "en", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-1050", "description": "Excessive Platform Resource Consumption within a Loop"}]}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-04-02T16:35:02.691Z"}, "x_redhatCweChain": "CWE-1050: Excessive Platform Resource Consumption within a Loop"}}, "cveMetadata": {"cveId": "CVE-2026-4634", "state": "PUBLISHED", "dateUpdated": "2026-04-03T17:23:00.421Z", "dateReserved": "2026-03-23T08:41:40.650Z", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "datePublished": "2026-04-02T12:44:53.424Z", "assignerShortName": "redhat"}, "dataVersion": "5.2"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:text-only:*:*:*", "matchCriteriaId": "1830E455-7E11-4264-862D-05971A42D4A6", "vulnerable": true}, {"criteria": "cpe:2.3:a:redhat:build_of_keycloak:26.2:*:*:*:text-only:*:*:*", "matchCriteriaId": "C339EBE3-6BFD-4082-B904-4E8DB87AAE68", "vulnerable": true}, {"criteria": "cpe:2.3:a:redhat:build_of_keycloak:26.2.15:*:*:*:text-only:*:*:*", "matchCriteriaId": "3BDF8A92-727E-401B-80BB-A141DCB39750", "vulnerable": true}, {"criteria": "cpe:2.3:a:redhat:build_of_keycloak:26.4:*:*:*:text-only:*:*:*", "matchCriteriaId": "100AA077-7467-4F62-A8FD-88BC336972DF", "vulnerable": true}, {"criteria": "cpe:2.3:a:redhat:build_of_keycloak:26.4.11:*:*:*:text-only:*:*:*", "matchCriteriaId": "17E79930-BE1C-4901-AF63-36B3EB149AFC", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server."}], "id": "CVE-2026-4634", "lastModified": "2026-04-16T20:50:10.327", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "secalert@redhat.com", "type": "Secondary"}]}, "published": "2026-04-02T13:16:27.027", "references": [{"source": "secalert@redhat.com", "tags": ["Vendor Advisory"], "url": "https://access.redhat.com/errata/RHSA-2026:6475"}, {"source": "secalert@redhat.com", "tags": ["Vendor Advisory"], "url": "https://access.redhat.com/errata/RHSA-2026:6476"}, {"source": "secalert@redhat.com", "tags": ["Vendor Advisory"], "url": "https://access.redhat.com/errata/RHSA-2026:6477"}, {"source": "secalert@redhat.com", "tags": ["Vendor Advisory"], "url": "https://access.redhat.com/errata/RHSA-2026:6478"}, {"source": "secalert@redhat.com", "tags": ["Vendor Advisory"], "url": "https://access.redhat.com/security/cve/CVE-2026-4634"}, {"source": "secalert@redhat.com", "tags": ["Issue Tracking", "Vendor Advisory"], "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450250"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-1050"}], "source": "secalert@redhat.com", "type": "Secondary"}]}

{"acknowledgement": "Red Hat would like to thank Slvrqn for reporting this issue.", "affected_release": [{"advisory": "RHSA-2026:6476", "cpe": "cpe:/a:redhat:build_keycloak:26.2::el9", "package": "rhbk/keycloak-operator-bundle:26.2.15-1", "product_name": "Red Hat build of Keycloak 26.2", "release_date": "2026-04-02T00:00:00Z"}, {"advisory": "RHSA-2026:6476", "cpe": "cpe:/a:redhat:build_keycloak:26.2::el9", "package": "rhbk/keycloak-rhel9:26.2-18", "product_name": "Red Hat build of Keycloak 26.2", "release_date": "2026-04-02T00:00:00Z"}, {"advisory": "RHSA-2026:6476", "cpe": "cpe:/a:redhat:build_keycloak:26.2::el9", "package": "rhbk/keycloak-rhel9-operator:26.2-18", "product_name": "Red Hat build of Keycloak 26.2", "release_date": "2026-04-02T00:00:00Z"}, {"advisory": "RHSA-2026:6475", "cpe": "cpe:/a:redhat:build_keycloak:26.2::el9", "package": "rhbk/keycloak-rhel9", "product_name": "Red Hat build of Keycloak 26.2.15", "release_date": "2026-04-02T00:00:00Z"}, {"advisory": "RHSA-2026:6478", "cpe": "cpe:/a:redhat:build_keycloak:26.4::el9", "package": "rhbk/keycloak-operator-bundle:26.4.11-1", "product_name": "Red Hat build of Keycloak 26.4", "release_date": "2026-04-02T00:00:00Z"}, {"advisory": "RHSA-2026:6478", "cpe": "cpe:/a:redhat:build_keycloak:26.4::el9", "package": "rhbk/keycloak-rhel9:26.4-14", "product_name": "Red Hat build of Keycloak 26.4", "release_date": "2026-04-02T00:00:00Z"}, {"advisory": "RHSA-2026:6478", "cpe": "cpe:/a:redhat:build_keycloak:26.4::el9", "package": "rhbk/keycloak-rhel9-operator:26.4-14", "product_name": "Red Hat build of Keycloak 26.4", "release_date": "2026-04-02T00:00:00Z"}, {"advisory": "RHSA-2026:6477", "cpe": "cpe:/a:redhat:build_keycloak:26.4::el9", "package": "rhbk/keycloak-rhel9", "product_name": "Red Hat build of Keycloak 26.4.11", "release_date": "2026-04-02T00:00:00Z"}], "bugzilla": {"description": "keycloak: Keycloak: Denial of Service via excessive processing of OpenID Connect scope parameters", "id": "2450250", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450250"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "verified"}, "cwe": "CWE-1050", "details": ["A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}, "name": "CVE-2026-4634", "public_date": "2026-04-02T12:30:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-4634\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-4634"], "statement": "This is an Important denial of service vulnerability in Red Hat Build of Keycloak (RHBK). An unauthenticated attacker can exploit this flaw by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect token endpoint, leading to high resource consumption and prolonged processing times on the Keycloak server.", "threat_severity": "Important"}