{"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": "2026-01-15T12:06:21.251Z"}, "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", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "org.keycloak/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/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": "2026-01-15T06:43:23.112000+00:00", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-01-15T00:00:00+00:00", "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": "2026-01-15T12:06:21.251Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

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{"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."}], "id": "CVE-2026-0976", "lastModified": "2026-01-15T13:16:04.910", "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": "Primary"}]}, "published": "2026-01-15T13:16:04.910", "references": [{"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": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}], "source": "secalert@redhat.com", "type": "Primary"}]}

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