CVE-2026-0976

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-0976", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-01-15T06:43:41.332Z", "datePublished": "2026-01-15T12:06:21.251Z", "dateUpdated": "2026-10-22T21:17:19.726Z"}, "containers": {"cna": {"title": "Org.keycloak/keycloak-quarkus-server: keycloak: proxy bypass due to improper handling of matrix parameters in url paths", "metrics": [{"other": {"content": {"value": "Low", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4.9", "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", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "keycloak-quarkus-server", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:build_keycloak:"]}, {"vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 8", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "keycloak-quarkus-server", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"]}, {"vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 8", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "keycloak-quarkus-server-app", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"]}, {"vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 8", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "keycloak-quarkus-server-deployment", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"]}, {"vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "keycloak-quarkus-server", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:jbosseapxp"]}, {"vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "keycloak-quarkus-server-app", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:jbosseapxp"]}, {"vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "keycloak-quarkus-server-deployment", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:jbosseapxp"]}], "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:2365", "name": "RHSA-2026:2365", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/security/cve/CVE-2026-0976", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2429869", "name": "RHBZ#2429869", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-01-15T00:00:00.000Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-20", "description": "Improper Input Validation", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-20: Improper Input Validation", "workarounds": [{"lang": "en", "value": "To mitigate this issue, ensure that all administrative and sensitive endpoints within Keycloak are adequately protected by robust authentication and authorization policies, independent of any reverse proxy path filtering. Operators should review Keycloak's internal access controls to confirm that access to these endpoints is restricted to authorized users and roles."}], "timeline": [{"lang": "en", "time": "2026-01-15T06:43:23.112Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-01-15T00:00:00.000Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Alexander Schwartz (RedHat) for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-10-22T21:17:19.726Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-01-15T14:44:09.361820Z", "id": "CVE-2026-0976", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"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": "2026-01-15T14:45:41.540Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-0976", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-01-15T14:44:09.361820Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-15T14:45:37.752Z"}}], "cna": {"title": "Org.keycloak/keycloak-quarkus-server: keycloak: proxy bypass due to improper handling of matrix parameters in url paths", "credits": [{"lang": "en", "value": "Red Hat would like to thank Alexander Schwartz (RedHat) for reporting this issue."}], "metrics": [{"other": {"type": "Red Hat severity rating", "content": {"value": "Low", "namespace": "https://access.redhat.com/security/updates/classification/"}}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.7, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}}], "affected": [{"cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"], "vendor": "Red Hat", "product": "Red Hat build of Keycloak 26.4.9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:"], "vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "packageName": "keycloak-quarkus-server", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 8", "packageName": "keycloak-quarkus-server", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 8", "packageName": "keycloak-quarkus-server-app", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 8", "packageName": "keycloak-quarkus-server-deployment", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jbosseapxp"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "packageName": "keycloak-quarkus-server", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jbosseapxp"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "packageName": "keycloak-quarkus-server-app", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jbosseapxp"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "packageName": "keycloak-quarkus-server-deployment", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "affected"}], "timeline": [{"lang": "en", "time": "2026-01-15T06:43:23.112Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-01-15T00:00:00.000Z", "value": "Made public."}], "datePublic": "2026-01-15T00:00:00.000Z", "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:2365", "name": "RHSA-2026:2365", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/security/cve/CVE-2026-0976", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2429869", "name": "RHBZ#2429869", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "workarounds": [{"lang": "en", "value": "To mitigate this issue, ensure that all administrative and sensitive endpoints within Keycloak are adequately protected by robust authentication and authorization policies, independent of any reverse proxy path filtering. Operators should review Keycloak's internal access controls to confirm that access to these endpoints is restricted to authorized users and roles."}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-20", "description": "Improper Input Validation"}]}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-10-22T21:17:19.726Z"}, "x_redhatCweChain": "CWE-20: Improper Input Validation"}}, "cveMetadata": {"cveId": "CVE-2026-0976", "state": "PUBLISHED", "dateUpdated": "2026-10-22T21:17:19.726Z", "dateReserved": "2026-01-15T06:43:41.332Z", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "datePublished": "2026-01-15T12:06:21.251Z", "assignerShortName": "redhat"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:build_keycloak:26.4::el9"], "defaultStatus": "unaffected", "product": "Red Hat build of Keycloak 26.4.9", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:build_keycloak:"], "defaultStatus": "affected", "packageName": "keycloak-quarkus-server", "product": "Red Hat Build of Keycloak", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"], "defaultStatus": "affected", "packageName": "keycloak-quarkus-server", "product": "Red Hat JBoss Enterprise Application Platform 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"], "defaultStatus": "affected", "packageName": "keycloak-quarkus-server-app", "product": "Red Hat JBoss Enterprise Application Platform 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "cpes": ["cpe:/a:redhat:jboss_enterprise_application_platform:8"], "defaultStatus": "affected", "packageName": "keycloak-quarkus-server-deployment", "product": "Red Hat JBoss Enterprise Application Platform 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "cpes": ["cpe:/a:redhat:jbosseapxp"], "defaultStatus": "affected", "packageName": "keycloak-quarkus-server", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "cpes": ["cpe:/a:redhat:jbosseapxp"], "defaultStatus": "affected", "packageName": "keycloak-quarkus-server-app", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "cpes": ["cpe:/a:redhat:jbosseapxp"], "defaultStatus": "affected", "packageName": "keycloak-quarkus-server-deployment", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "vendor": "Red Hat"}], "source": "secalert@redhat.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable."}, {"lang": "es", "value": "Se encontr\u00f3 un defecto en Keycloak. Esta vulnerabilidad de validaci\u00f3n de entrada incorrecta ocurre porque Keycloak acepta par\u00e1metros de matriz conformes con RFC en segmentos de ruta de URL, mientras que las configuraciones comunes de proxy inverso pueden ignorarlos o manejarlos incorrectamente. Un atacante remoto puede elaborar solicitudes para enmascarar segmentos de ruta, eludiendo potencialmente el filtrado de rutas a nivel de proxy. Esto podr\u00eda exponer puntos finales administrativos o sensibles que los operadores creen que no son accesibles externamente."}], "id": "CVE-2026-0976", "lastModified": "2026-10-22T22:17:41.857", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 1.4, "source": "secalert@redhat.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-0976", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-01-15T14:44:09.361820Z", "version": "2.0.3"}}]}, "published": "2026-01-15T13:16:04.910", "references": [{"source": "secalert@redhat.com", "url": "https://access.redhat.com/errata/RHSA-2026:2365"}, {"source": "secalert@redhat.com", "url": "https://access.redhat.com/security/cve/CVE-2026-0976"}, {"source": "secalert@redhat.com", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2429869"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}], "source": "secalert@redhat.com", "type": "Secondary"}]}

{"acknowledgement": "Red Hat would like to thank Alexander Schwartz (RedHat) for reporting this issue.", "bugzilla": {"description": "org.keycloak/keycloak-quarkus-server: Keycloak: Proxy bypass due to improper handling of matrix parameters in URL paths", "id": "2429869", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2429869"}, "csaw": false, "cvss3": {"cvss3_base_score": "3.7", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N", "status": "draft"}, "cwe": "CWE-20", "details": ["A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, ensure that all administrative and sensitive endpoints within Keycloak are adequately protected by robust authentication and authorization policies, independent of any reverse proxy path filtering. Operators should review Keycloak's internal access controls to confirm that access to these endpoints is restricted to authorized users and roles."}, "name": "CVE-2026-0976", "package_state": [{"cpe": "cpe:/a:redhat:build_keycloak:", "fix_state": "Affected", "package_name": "org.keycloak/keycloak-quarkus-server", "product_name": "Red Hat Build of Keycloak"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_application_platform:8", "fix_state": "Fix deferred", "package_name": "keycloak-quarkus-server", "product_name": "Red Hat JBoss Enterprise Application Platform 8"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_application_platform:8", "fix_state": "Fix deferred", "package_name": "keycloak-quarkus-server-app", "product_name": "Red Hat JBoss Enterprise Application Platform 8"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_application_platform:8", "fix_state": "Fix deferred", "package_name": "keycloak-quarkus-server-deployment", "product_name": "Red Hat JBoss Enterprise Application Platform 8"}, {"cpe": "cpe:/a:redhat:jbosseapxp", "fix_state": "Fix deferred", "package_name": "keycloak-quarkus-server", "product_name": "Red Hat JBoss Enterprise Application Platform Expansion Pack"}, {"cpe": "cpe:/a:redhat:jbosseapxp", "fix_state": "Fix deferred", "package_name": "keycloak-quarkus-server-app", "product_name": "Red Hat JBoss Enterprise Application Platform Expansion Pack"}, {"cpe": "cpe:/a:redhat:jbosseapxp", "fix_state": "Fix deferred", "package_name": "keycloak-quarkus-server-deployment", "product_name": "Red Hat JBoss Enterprise Application Platform Expansion Pack"}], "public_date": "2026-01-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-0976\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-0976"], "statement": "This vulnerability is rated Low for Red Hat Keycloak. The flaw arises from Keycloak's acceptance of RFC-compliant matrix parameters in URL paths, which can be mishandled by certain reverse proxy configurations. This may allow an unauthenticated attacker to bypass proxy-level path filtering and potentially expose administrative or sensitive endpoints that are intended to be unreachable externally. Exploitation depends on the specific reverse proxy configuration.", "threat_severity": "Low"}

{"analysis": {"en": {"generated_at": "2026-04-18T19:12:16.279800+00:00", "value": {"mitigation_remediation": ["Ensure that all administrative and sensitive endpoints within Keycloak are protected by robust authentication and authorization policies, independent of any reverse proxy path filtering.", "Review Keycloak\u2019s internal access controls to confirm that access to these endpoints is restricted to authorized users and roles.", "Configure the reverse proxy or Keycloak deployment to strip or reject matrix parameters in URL path segments, disabling the bypass capability."], "summary": {"action": "Apply Controls", "impact": "Remote Path Bypass"}, "threat_synthesis": {"affected_systems": "Red\u00a0Hat Build of Keycloak, Red\u00a0Hat JBoss Enterprise Application Platform\u202f8, and Red\u00a0Hat JBoss Enterprise Application Platform Expansion Pack are affected. No specific version ranges are listed, so all installed instances of these products should be evaluated for exposure to this issue.", "description_and_impact": "Keycloak accepts RFC-compliant matrix parameters in URL path segments. When a reverse proxy does not preserve or properly handle these parameters, an attacker can craft requests that hide privileged path segments, thereby bypassing proxy-level path filtering. The vulnerability is an input validation flaw (CWE\u201120) that allows a remote attacker to send a single HTTP request containing matrix parameters to a Keycloak instance and potentially reach endpoints that operators assume are not externally reachable.", "risk_and_exploitability": "The CVSS base score is 3.7, indicating low severity. Exploitation requires only remote access to transmit a crafted request. The EPSS score is below 1\u202f%, suggesting that exploitation attempts are rare. The vulnerability is not listed in the CISA KEV catalog. Because the attack can be performed over the public network, operators should address the weakness if their protective controls for administrative endpoints are insufficient."}}}}, "created": "2026-04-18T19:15:10.615507+00:00", "updated": "2026-04-18T19:15:10.615519+00:00", "vendors": []}