CVE-2026-84439
- Source
- https://cve.org/CVERecord?id=CVE-2026-84439
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84439.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-84439
- Aliases
- Downstream
- Published
- 2026-09-16T09:27:46Z
- Modified
- 2026-09-20T11:46:42Z
- Severity
-
- 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
- Summary
- Apache ZooKeeper: Audit log injection via unsanitized output from multiple sources
- 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.
A 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.
This issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6.
Users are recommended to upgrade to version 3.9.6 or 3.8.7, which fixes the issue.
- Database specific
{ "cna_assigner": "apache", "cwe_ids": [ "CWE-117" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84439.json", "unresolved_ranges": [ { "extracted_events": [ { "introduced": "3.9.0" }, { "last_affected": "3.9.5" }, { "introduced": "3.8.0" }, { "last_affected": "3.8.6" } ], "source": "AFFECTED_FIELD" }, { "extracted_events": [ { "introduced": "3.9.0" }, { "fixed": "3.9.5" }, { "introduced": "3.8.0" }, { "fixed": "3.8.6" } ], "source": "DESCRIPTION" } ] }- References