Description
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.
References (10)
Core 10
Core References
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:10184
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:14272
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:14276
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:8509
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-24281
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2445449
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:34608
Mailing List vendor-advisory
https://lists.apache.org/thread/088ddsbrzhd5lxzbqf5n24yg0mwh9jt2
Scores
CVSS v3
7.4
EPSS
0.0063
EPSS Percentile
46.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-295
CWE-350
Status
published
Products (4)
apache/zookeeper
3.8.0 - 3.8.6
Apache Software Foundation/Apache ZooKeeper
3.8.0 - 3.8.5
Apache Software Foundation/Apache ZooKeeper
3.9.0 - 3.9.4
org.apache.zookeeper/zookeeper
3.8.0 - 3.8.6Maven
Published
Mar 07, 2026
Tracked Since
Mar 07, 2026