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    "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": "2026-09-16T10:12:02.894Z"
    },
    "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 — with arbitrary timestamps, log levels, class names, and messages — 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": [
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                            "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 — with arbitrary timestamps, log levels, class names, and messages — 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"
                    ]
                }
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            "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"
                }
            ],
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                "engine": "Vulnogram 1.0.3"
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        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "http://www.openwall.com/lists/oss-security/2026/09/15/7"
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}