CVE-2026-24308
HighCVSS 7.5Exploitation Probability (EPSS)
Elevated risk64th percentile - higher than 64% of all known CVEs
Summary
In Apache ZooKeeper versions 3.8.5 and 3.9.4, improper handling of configuration values in ZKConfig allows an attacker to expose sensitive information stored in client configuration in the client's logfile. Configuration values are exposed at INFO level logging, potentially affecting production systems.
Risk Assessment
The risk involves leakage of sensitive configuration data, such as passwords or API keys, into log files. This could allow an attacker to access confidential information and further escalate attacks in a production environment.
Recommendation
Upgrade Apache ZooKeeper to version 3.8.6 or 3.9.5 immediately to fix this vulnerability. After upgrading, review existing log files for any leaked sensitive data.
Other vulnerabilities in Apache ZooKeeper
See all- CVE-2017-5637High
Two four-letter commands 'wchp/wchc' are CPU intensive and can cause a spike in CPU utilization on the Apache ZooKeeper server if abused, leading to the server being unable to serve legitimate client requests.
- CVE-2016-5017High
Buffer overflow in the C cli shell in Apache Zookeeper before version 3.4.9 and 3.5.x before version 3.5.3, occurring when using the 'cmd:' batch mode syntax, allows attackers to have unspecified impact via a long command string.
- CVE-2026-84501Medium
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. The ensemble name is not sanitized before being logged, allowing the attacker to forge log entries indistinguishable from genuine ones.
- CVE-2026-84439Medium
When audit logging is enabled, an unauthenticated attacker can inject arbitrary fields into Apache ZooKeeper's audit log by sending a digest authentication request with tab characters in the username. The injected tabs are parsed as field separators, allowing the attacker to spoof audit results and operations.
- CVE-2026-79993High
In Apache ZooKeeper, the deleteContainer opcode (0x14/20) is processed without verifying ACL permissions, allowing any authenticated client to delete empty persistent, container, and TTL nodes even without proper permissions. This is an authorization bypass and ACL enforcement bug.
- CVE-2026-59969High
In Apache ZooKeeper, in FIPS mode, peer hostname verification in quorum TLS is not enforced. Despite enabling the relevant options, the connection accepts a CA-trusted certificate even if the SAN does not match the connected host, allowing a malicious certificate to join quorum traffic.
- CVE-2026-59739High
In Apache ZooKeeper, there is an information disclosure via SetWatches reconnect replay due to missing ACL check. An attacker can discover ACL-restricted paths by registering exists-watches on non-existent paths, then reconnecting after the paths are created with restricted ACLs.
- CVE-2026-24281High
In Apache ZooKeeper, hostname verification in ZKTrustManager falls back to reverse DNS (PTR) when IP SAN validation fails, allowing attackers who control or spoof PTR records to impersonate ZooKeeper servers or clients with a valid certificate for the PTR name. The attacker must present a certificate trusted by ZKTrustManager, making the attack vector harder to exploit.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS