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.

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Source ID Title
Github GHSA Github GHSA GHSA-7xrh-hqfc-g7qr Apache ZooKeeper: Reverse-DNS fallback enables hostname verification bypass in ZooKeeper ZKTrustManager
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 10 Mar 2026 18:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}


Tue, 10 Mar 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N'}

threat_severity

Moderate


Mon, 09 Mar 2026 10:15:00 +0000

Type Values Removed Values Added
First Time appeared Apache
Apache zookeeper
Vendors & Products Apache
Apache zookeeper

Sat, 07 Mar 2026 17:30:00 +0000

Type Values Removed Values Added
References

Sat, 07 Mar 2026 09:00:00 +0000

Type Values Removed Values Added
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.
Title Apache ZooKeeper: Reverse-DNS fallback enables hostname verification bypass in ZooKeeper ZKTrustManager
Weaknesses CWE-295
CWE-350
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-03-10T17:37:28.087Z

Reserved: 2026-01-21T19:40:25.776Z

Link: CVE-2026-24281

cve-icon Vulnrichment

Updated: 2026-03-07T17:05:10.486Z

cve-icon NVD

Status : Modified

Published: 2026-03-07T09:16:07.437

Modified: 2026-03-10T18:18:17.727

Link: CVE-2026-24281

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-07T08:50:32Z

Links: CVE-2026-24281 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-03-09T10:05:29Z

Weaknesses