CVE-2026-84501
- Source
- https://cve.org/CVERecord?id=CVE-2026-84501
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84501.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-84501
- Aliases
- Downstream
- Published
- 2026-09-16T09:28:10Z
- Modified
- 2026-09-20T11:47:27Z
- 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: Operational log forgery via newline injection in EnsembleAuthenticationProvider
- 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 — with arbitrary timestamps, log levels, class names, and messages — that are visually indistinguishable from genuine ZooKeeper log output.
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 3.8.7 or 3.9.6, 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-2026-84501.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