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Fencer Vulns
high 7.4

CVE-2026-24281 json

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

published 2026-03-07 8 mo ago modified 2026-09-10 1 mo ago also BIT-zookeeper-2026-24281 , EUVD-2026-10139 , GHSA-7xrh-hqfc-g7qr

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.apache.zookeeper:zookeeper 3.8.6, 3.9.5
  • bitnami zookeeper 3.8.6, 3.9.5
  • Red Hat Red Hat OpenShift AI 2.25 1776756834
  • zookeeper Debian 14 3.9.5-1

debian advisories DEBIAN-CVE-2026-24281

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-24281 updated cvss 7.4

Apache ZooKeeper: Apache ZooKeeper: Impersonation of servers or clients via reverse DNS spoofing

  • Red Hat build of Debezium 2 zookeeper Red Hat build of Debezium 3 zookeeper Red Hat Fuse 7 zookeeper
    affected: workaround, no fix planned “Will not fix”
  • Red Hat JBoss Enterprise Application Platform Expansion Pack zookeeper Red Hat Offline Knowledge Portal offline-knowledge-portal/rhokp-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-modelmesh-rhel8
    affected: workaround, no fix available
  • Red Hat streams for Apache Kafka 3 zookeeper
    affected: workaround, no fix planned “Will not fix”
  • Red Hat AMQ Broker 7.12.7
    fixed: vendor fix RHSA-2026:14276
  • Red Hat AMQ Broker 7.13.5
    fixed: vendor fix RHSA-2026:14272
  • Red Hat AMQ Broker 7.14.0
    fixed: vendor fix RHSA-2026:8509
  • Red Hat JBoss Enterprise Application Platform 6.0.4.GA zookeeper 3.8.6.redhat-00001
    fixed: vendor fix RHSA-2026:19678
  • Red Hat OpenShift AI 2.25 rhoai 1776756834
    fixed: vendor fix RHSA-2026:10184
show 5 more
  • Red Hat Streams for Apache Kafka 2.9.4
    fixed: vendor fix RHSA-2026:34608
  • Red Hat build of Apache Camel for Spring Boot 4 zookeeper Red Hat Data Grid 8 zookeeper
    not affected: component not present
  • Red Hat JBoss Enterprise Application Platform 6.0.4.GA pom.xml, liblz4-java.so, libsnappyjava.so, commons-logging 1.2, wc-chatbot-0.1.2.jar, commons-beanutils 1.9.4, +256 more Red Hat JBoss Enterprise Application Platform 7 zookeeper
    not affected: vulnerable code not present
  • Red Hat JBoss Enterprise Application Platform 8 zookeeper
    not affected: component not present
  • Red Hat OpenShift AI 2.25 rhoai 1775144403, rhoai 1776243157, rhoai 1776243163, rhoai 1776243192, rhoai 1776243217, rhoai 1776243229, +70 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

0.69% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CISA ADP 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
OSV 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
maven org.apache.zookeeper:zookeeper
>=3.8.0, <3.8.6
>=3.9.0, <3.9.5
3.8.6
3.9.5
bitnami zookeeper
>=3.8.0, <3.8.6
>=3.9.0, <3.9.5
3.8.6
3.9.5

Affected products

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

Classification

Weakness
  • CWE-350 Reliance on Reverse DNS Resolution for a Security-Critical Action
  • CWE-295 Improper Certificate Validation
  • CWE-297 Improper Validation of Certificate with Host Mismatch
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.