CVE-2026-24308 in ZooKeeper
Summary
by MITRE • 03/07/2026
Improper handling of configuration values in ZKConfig in Apache ZooKeeper 3.8.5 and 3.9.4 on all platforms allows an attacker to expose sensitive information stored in client configuration in the client's logfile. Configuration values are exposed at INFO level logging rendering potential production systems affected by the issue. Users are recommended to upgrade to version 3.8.6 or 3.9.5 which fixes this issue.
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Analysis
by VulDB Data Team • 07/23/2026
The vulnerability identified as CVE-2026-24308 represents a critical configuration exposure flaw within Apache ZooKeeper's ZKConfig component affecting versions 3.8.5 and 3.9.4 across all platforms. This issue stems from improper handling of configuration values during the logging process, where sensitive information contained within client configurations becomes inadvertently written to log files at INFO level verbosity. The flaw demonstrates a fundamental weakness in how the system manages sensitive data during runtime operations, creating potential attack vectors for adversaries who may gain access to system logs.
The technical implementation of this vulnerability occurs within the ZKConfig module where configuration parameters are processed and subsequently logged without proper sanitization or filtering mechanisms. When ZooKeeper clients operate with sensitive configuration data such as authentication tokens, connection strings, or credential information, these values are directly incorporated into log entries at INFO level logging severity. This logging behavior violates security best practices by exposing confidential information in plaintext within log files that may be accessible to unauthorized users or processes. The vulnerability is particularly concerning because INFO level logging is typically enabled in production environments, making the exposure persistent and widespread.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential privilege escalation and lateral movement opportunities within compromised environments. Attackers who can access system logs may extract sensitive configuration values including user credentials, service endpoints, and authentication mechanisms that could be leveraged for further exploitation. This exposure creates opportunities for attackers to perform unauthorized access attempts against other systems that rely on the same configuration parameters or to establish persistence within the network infrastructure. The vulnerability affects all platforms where Apache ZooKeeper operates, making it a universal concern for organizations running these versions regardless of their specific deployment environments.
Security practitioners should recognize this vulnerability as a direct violation of CWE-209, which addresses "Information Exposure Through an Error Message," and aligns with ATT&CK technique T1562.001 for "Disable or Modify Tools." The improper logging of sensitive configuration values creates an information disclosure risk that can be exploited by threat actors to gain intelligence about system configurations and operational parameters. Organizations must implement immediate mitigations including upgrading to Apache ZooKeeper versions 3.8.6 or 3.9.5, which contain the necessary patches to prevent sensitive data exposure in log files. Additionally, system administrators should review existing log configurations to ensure that sensitive information is not being logged at INFO level or higher, and consider implementing log sanitization processes to remove or mask sensitive data from system outputs. The vulnerability highlights the critical importance of secure logging practices and proper configuration management in distributed systems where sensitive data flows through multiple components and logging mechanisms.