Apache ZooKeeper <=3.8.5 ZKTrustManager Reverse DNS Fallback
CVE-2026-24281 Published on March 7, 2026

Apache ZooKeeper: Reverse-DNS fallback enables hostname verification bypass in ZooKeeper ZKTrustManager
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.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-24281 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
NONE

Weakness Types

Reliance on Reverse DNS Resolution for a Security-Critical Action

The software performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname.

Improper Certificate Validation

The software does not validate, or incorrectly validates, a certificate. When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The software might connect to a malicious host while believing it is a trusted host, or the software might be deceived into accepting spoofed data that appears to originate from a trusted host.


Products Associated with CVE-2026-24281

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-24281 are published in these products:

Apache Zookeeper
 
Red Hat Amq Broker
 
Red Hat Openshift Ai
 
Red Hat Debezium
 
Red Hat Jboss Fuse
 
Red Hat Jbosseapxp
 
Red Hat Offline Knowledge Portal
 
Red Hat Amq Streams
 
Red Hat Camel Spring Boot
 
Red Hat Jboss Data Grid
 
Red Hat Jboss Enterprise Application Platform
 
Red Hat Kafka
 

Affected Versions

Apache Software Foundation Apache ZooKeeper: Red Hat AMQ Broker 7.12.7: Red Hat AMQ Broker 7.13.5: Red Hat AMQ Broker 7.14.0: Red Hat Streams for Apache Kafka 2.9.4: Red Hat OpenShift AI 2.25: Red Hat build of Apache Camel for Spring Boot 4: Red Hat build of Debezium 2: Red Hat build of Debezium 3: Red Hat Data Grid 8: Red Hat Fuse 7: Red Hat JBoss Enterprise Application Platform 7: Red Hat JBoss Enterprise Application Platform 8: Red Hat JBoss Enterprise Application Platform Expansion Pack: Red Hat Offline Knowledge Portal: Red Hat OpenShift AI (RHOAI): Red Hat streams for Apache Kafka 3:

Exploit Probability

EPSS
0.31%
Percentile
22.05%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.