CVE-2026-84501

Published: Set 16, 2026 Last Modified: Set 16, 2026
ExploitDB:
Other exploit source:
Google Dorks:
MEDIUM 5,3
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: low
Availability: none

Description

AI Translation Available

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.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0023
Percentile
0,1th
Updated

Single Data Point

Only one EPSS measurement is available for this CVE. Trend analysis requires multiple data points over time.

117

Improper Output Neutralization for Logs

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability Non-Repudiation
Potential Impacts:
Modify Application Data Hide Activities Execute Unauthorized Code Or Commands
Applicable Platforms
All platforms may be affected
Likelihood of Exploit: Medium
View CWE Details
http://www.openwall.com/lists/oss-security/2026/09/15/7
http://www.openwall.com/lists/oss-security/2026/09/15/7
https://lists.apache.org/thread/ohby1g6zjt72p0w79rhbr41nczz…
https://lists.apache.org/thread/ohby1g6zjt72p0w79rhbr41nczzvr33y