CVE-2026-84439

{"id": "CVE-2026-84439", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-84439", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-17T19:14:36.442526Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"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"}, "impactScore": 1.4, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@apache.org", "affectedData": [{"vendor": "Apache Software Foundation", "product": "Apache ZooKeeper", "versions": [{"status": "affected", "version": "3.9.0", "versionType": "maven", "lessThanOrEqual": "3.9.5"}, {"status": "affected", "version": "3.8.0", "versionType": "maven", "lessThanOrEqual": "3.8.6"}], "packageURL": "pkg:maven/org.apache.zookeeper/zookeeper", "packageName": "org.apache.zookeeper:zookeeper", "collectionURL": "https://repo.maven.apache.org/maven2", "defaultStatus": "unaffected"}]}], "published": "2026-09-16T10:16:53.433", "references": [{"url": "https://lists.apache.org/thread/b7qnjvqjh393l0j07tmnb5ggg40sx3m6", "tags": ["Mailing List", "Vendor Advisory"], "source": "security@apache.org"}, {"url": "http://www.openwall.com/lists/oss-security/2026/09/15/6", "tags": ["Mailing List", "Vendor Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security@apache.org", "description": [{"lang": "en", "value": "CWE-117"}]}], "descriptions": [{"lang": "en", "value": "When audit logging is enabled (zookeeper.audit.enable=true), an unauthenticated attacker can inject arbitrary fields into Apache ZooKeeper's audit log by sending a digest authentication request with tab characters (\\t) embedded in the username. Because the audit log uses tab-separated\u00a0key=value\u00a0format, the injected tabs are parsed as legitimate field separators, allowing the attacker to spoof audit results (e.g., injecting\u00a0result=success), forge operation types, and corrupt forensic evidence.\n\nA log injection vulnerability in Apache ZooKeeper allows a client that can call\u00a0setACL\u00a0to inject forged key-value fields into\u00a0zookeeper_audit.log. When audit logging is enabled, the server serializes attacker-controlled digest ACL ids into the\u00a0acl=\u00a0audit field without escaping tab characters. Because audit events are emitted as tab-separated\u00a0key=value\u00a0records, a crafted ACL id can make one successful\u00a0setAcl\u00a0event appear to contain forged fields such as\u00a0operation=delete\u00a0and\u00a0znode=/forged. This undermines the integrity of downstream audit parsing, alerting, and incident response.\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 3.9.6 or 3.8.7, which fixes the issue."}], "lastModified": "2026-09-18T14:37:30.650", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4EB0BE5E-6F39-4D77-BBEC-89AE61429E31", "versionEndExcluding": "3.8.7", "versionStartIncluding": "3.8.0"}, {"criteria": "cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "78E0C560-E216-4628-9131-E8C919D8B937", "versionEndExcluding": "3.9.6", "versionStartIncluding": "3.9.0"}], "operator": "OR"}]}], "sourceIdentifier": "security@apache.org"}