CVE-2026-24281
HighCVSS 7.4Exploitation Probability (EPSS)
Low risk46th percentile - higher than 46% of all known CVEs
Summary
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.
Risk Assessment
The organization is at risk of impersonation of trusted ZooKeeper servers or clients, potentially leading to unauthorized data access or disruption of distributed systems.
Recommendation
Upgrade Apache ZooKeeper to version 3.8.6 or 3.9.5 immediately, which introduce a configuration option to disable reverse DNS lookup in client and quorum protocols.
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-2026-24308High
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.
Original NVD description (English source)
Hostname verification in Apache ZooKeeper 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. It's important to note that attacker must present a certificate which is trusted by ZKTrustManager which makes the attack vector harder to exploit. Users are recommended to upgrade to version 3.8.6 or 3.9.5, which fixes this issue by introducing a new configuration option to disable reverse DNS lookup in client and quorum protocols.