๐Ÿ” CVE Alert

CVE-2026-24281

MEDIUM 5.9

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

CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-350 CWE-295
Vendor apache software foundation
Product apache zookeeper
Published Mar 7, 2026
Last Updated Mar 10, 2026
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Affected Versions

Apache Software Foundation / Apache ZooKeeper
3.9.0 โ‰ค 3.9.4 3.8.0 โ‰ค 3.8.5

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
lists.apache.org: https://lists.apache.org/thread/088ddsbrzhd5lxzbqf5n24yg0mwh9jt2 openwall.com: http://www.openwall.com/lists/oss-security/2026/03/07/4

Credits

๐Ÿ” Nikita Markevich <[email protected]>