CVE-2026-84501
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2026
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
Apache ZooKeeper: Operational log forgery via newline injection in EnsembleAuthenticationProvider
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.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Apache ZooKeeper
- Vendor
- Apache Software Foundation
- Product
- Apache ZooKeeper
- Platforms
- Unknown
- Default status
unaffected- Package
- org.apache.zookeeper:zookeeper
- Package collection
- https://repo.maven.apache.org/maven2
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 3.9.0 | affected | maven | Unavailable | 3.9.5 | None listed |
| 3.8.0 | affected | maven | Unavailable | 3.8.6 | None listed |