{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "zookeeper",
        "purl": "pkg:bitnami/zookeeper"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.8.0"
            },
            {
              "fixed": "3.8.7"
            },
            {
              "introduced": "3.9.0"
            },
            {
              "fixed": "3.9.6"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-84439"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "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 key=value format, the injected tabs are parsed as legitimate field separators, allowing the attacker to spoof audit results (e.g., injecting result=success), forge operation types, and corrupt forensic evidence.\n\nA log injection vulnerability in Apache ZooKeeper allows a client that can call setACL to inject forged key-value fields into zookeeper_audit.log. When audit logging is enabled, the server serializes attacker-controlled digest ACL ids into the acl= audit field without escaping tab characters. Because audit events are emitted as tab-separated key=value records, a crafted ACL id can make one successful setAcl event appear to contain forged fields such as operation=delete and znode=/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.",
  "id": "BIT-zookeeper-2026-84439",
  "modified": "2026-09-19T09:02:05.474Z",
  "published": "2026-09-19T08:51:29.865Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/15/6"
    },
    {
      "type": "ADVISORY",
      "url": "https://lists.apache.org/thread/b7qnjvqjh393l0j07tmnb5ggg40sx3m6"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-84439"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Apache ZooKeeper: Audit log injection via unsanitized output from multiple sources"
}