{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-84501", "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09", "state": "PUBLISHED", "assignerShortName": "apache", "dateReserved": "2026-09-01T20:56:03.868Z", "datePublished": "2026-09-16T09:28:10.294Z", "dateUpdated": "2026-09-16T19:43:09.161Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09", "shortName": "apache", "dateUpdated": "2026-09-16T09:28:10.294Z"}, "title": "Apache ZooKeeper: Operational log forgery via newline injection in EnsembleAuthenticationProvider", "problemTypes": [{"descriptions": [{"description": "CWE-117 Improper output neutralization for logs", "lang": "en", "cweId": "CWE-117", "type": "CWE"}]}], "source": {"discovery": "UNKNOWN"}, "affected": [{"vendor": "Apache Software Foundation", "product": "Apache ZooKeeper", "collectionURL": "https://repo.maven.apache.org/maven2", "packageName": "org.apache.zookeeper:zookeeper", "packageURL": "pkg:maven/org.apache.zookeeper/zookeeper", "versions": [{"status": "affected", "version": "3.9.0", "lessThanOrEqual": "3.9.5", "versionType": "maven"}, {"status": "affected", "version": "3.8.0", "lessThanOrEqual": "3.8.6", "versionType": "maven"}], "defaultStatus": "unaffected"}], "descriptions": [{"value": "An unauthenticated attacker can inject arbitrary fake log lines into Apache ZooKeeper's operational log by sending a crafted add_auth(\"ensemble\", ...) request containing newline characters (\\n). When the ensemble name doesn't match, EnsembleAuthenticationProvider.handleAuthentication() logs the raw, unsanitized name via LOG.warn(). Because SLF4J's {} placeholder preserves embedded newlines, the attacker can forge complete log entries \u2014 with arbitrary timestamps, log levels, class names, and messages \u2014 that are visually indistinguishable from genuine ZooKeeper log output.\n\nThis issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6.\n\nUsers are recommended to upgrade to version 3.8.7 or 3.9.6, which fixes the issue.", "lang": "en", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>An unauthenticated attacker can inject arbitrary fake log lines into Apache ZooKeeper's operational log by sending a crafted add_auth(\"ensemble\", ...) request containing newline characters (\\n). When the ensemble name doesn't match, EnsembleAuthenticationProvider.handleAuthentication() logs the raw, unsanitized name via LOG.warn(). Because SLF4J's {} placeholder preserves embedded newlines, the attacker can forge complete log entries \u2014 with arbitrary timestamps, log levels, class names, and messages \u2014 that are visually indistinguishable from genuine ZooKeeper log output.<br><span><br>This issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6.<br></span><span><br>Users are recommended to upgrade to version 3.8.7 or 3.9.6, which fixes the issue.</span></p>"}]}], "references": [{"url": "https://lists.apache.org/thread/ohby1g6zjt72p0w79rhbr41nczzvr33y", "tags": ["vendor-advisory"]}], "metrics": [{"other": {"type": "Textual description of severity", "content": {"text": "moderate"}}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "credits": [{"lang": "en", "value": "Youlong Chen Institute of Computing Technology <chenyoulong20g@ict.ac.cn>", "type": "finder"}], "x_generator": {"engine": "Vulnogram 1.0.3"}}, "adp": [{"title": "CVE Program Container", "references": [{"url": "http://www.openwall.com/lists/oss-security/2026/09/15/7"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-09-16T10:12:02.894Z"}}, {"metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-09-16T19:42:27.138755Z", "id": "CVE-2026-84501", "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": "2026-09-16T19:43:09.161Z"}}]}}

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{"bugzilla": {"description": "zookeeper: Apache ZooKeeper: Operational log forgery via newline injection", "id": "2535096", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2535096"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "status": "draft"}, "cwe": "CWE-117", "details": ["An unauthenticated attacker can inject arbitrary fake log lines into Apache ZooKeeper's operational log by sending a crafted add_auth(\"ensemble\", ...) request containing newline characters (\\n). When the ensemble name doesn't match, EnsembleAuthenticationProvider.handleAuthentication() logs the raw, unsanitized name via LOG.warn(). Because SLF4J's {} placeholder preserves embedded newlines, the attacker can forge complete log entries \u2014 with arbitrary timestamps, log levels, class names, and messages \u2014 that are visually indistinguishable from genuine ZooKeeper log output.\nThis issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6.\nUsers are recommended to upgrade to version 3.8.7 or 3.9.6, which fixes the issue.", "A flaw was found in Apache ZooKeeper. An unauthenticated attacker can inject arbitrary fake log lines into the operational log by sending a specially crafted request containing newline characters. This vulnerability allows the attacker to forge complete log entries, including timestamps, log levels, and messages. These forged entries are visually indistinguishable from genuine ZooKeeper log output, which could lead to misinterpretation of system activity and hinder incident response efforts."], "mitigation": {"lang": "en:us", "value": "Update to Apache ZooKeeper 3.8.7, 3.9.6, or later."}, "name": "CVE-2026-84501", "package_state": [{"cpe": "cpe:/a:redhat:amq_broker:7", "fix_state": "Affected", "package_name": "parent", "product_name": "Red Hat AMQ Broker 7"}, {"cpe": "cpe:/a:redhat:amq_broker:7", "fix_state": "Affected", "package_name": "zookeeper", "product_name": "Red Hat AMQ Broker 7"}, {"cpe": "cpe:/a:redhat:amq_broker:7", "fix_state": "Affected", "package_name": "zookeeper-jute", "product_name": "Red Hat AMQ Broker 7"}, {"cpe": "cpe:/a:redhat:camel_quarkus:3", "fix_state": "Affected", "package_name": "flink-shaded-zookeeper-3", "product_name": "Red Hat build of Apache Camel 4 for Quarkus 3"}, {"cpe": "cpe:/a:redhat:camel_spring_boot:4", "fix_state": "Affected", "package_name": "flink-shaded-zookeeper-3", "product_name": "Red Hat build of Apache Camel for Spring Boot 4"}, {"cpe": "cpe:/a:redhat:camel_spring_boot:4", "fix_state": "Affected", "package_name": "flink-shaded-zookeeper-parent", "product_name": "Red Hat build of Apache Camel for Spring Boot 4"}, {"cpe": "cpe:/a:redhat:jboss_fuse:7", "fix_state": "Affected", "package_name": "camel-zookeeper", "product_name": "Red Hat Fuse 7"}, {"cpe": "cpe:/a:redhat:jboss_fuse:7", "fix_state": "Affected", "package_name": "camel-zookeeper-master", "product_name": "Red Hat Fuse 7"}, {"cpe": "cpe:/a:redhat:jboss_fuse:7", "fix_state": "Affected", "package_name": "org.linkedin.zookeeper-impl", "product_name": "Red Hat Fuse 7"}, {"cpe": "cpe:/a:redhat:jboss_fuse:7", "fix_state": "Affected", "package_name": "zookeeper", "product_name": "Red Hat Fuse 7"}, {"cpe": "cpe:/a:redhat:jboss_fuse:7", "fix_state": "Affected", "package_name": "zookeeper-jute", "product_name": "Red Hat Fuse 7"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_application_platform:8", "fix_state": "Affected", "package_name": "parent", "product_name": "Red Hat JBoss Enterprise Application Platform 8"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_application_platform:8", "fix_state": "Affected", "package_name": "zookeeper", "product_name": "Red Hat JBoss Enterprise Application Platform 8"}, {"cpe": "cpe:/a:redhat:jbosseapxp", "fix_state": "Affected", "package_name": "parent", "product_name": "Red Hat JBoss Enterprise Application Platform Expansion Pack"}, {"cpe": "cpe:/a:redhat:jbosseapxp", "fix_state": "Affected", "package_name": "zookeeper", "product_name": "Red Hat JBoss Enterprise Application Platform Expansion Pack"}, {"cpe": "cpe:/a:redhat:offline_knowledge_portal:1", "fix_state": "Affected", "package_name": "offline-knowledge-portal/rhokp-rhel9", "product_name": "Red Hat Offline Knowledge Portal"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-modelmesh-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-spark-operator-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th06-cpu-torch210-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th06-cpu-torch291-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th06-cuda130-torch210-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th06-cuda130-torch291-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th06-rocm64-torch291-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th-torch-cpu-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-th-torch-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openstack:13", "fix_state": "Affected", "package_name": "puppet-zookeeper", "product_name": "Red Hat OpenStack Platform 13 (Queens)"}, {"cpe": "cpe:/a:redhat:openstack:16.2", "fix_state": "Affected", "package_name": "puppet-zookeeper", "product_name": "Red Hat OpenStack Platform 16.2"}], "public_date": "2026-09-16T09:28:10Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-84501\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-84501\nhttps://lists.apache.org/thread/ohby1g6zjt72p0w79rhbr41nczzvr33y"], "statement": "A flaw was found in Apache ZooKeeper. 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