GHSA-7xrh-hqfc-g7qr
Apache ZooKeeper: Reverse-DNS fallback enables hostname verification bypass in ZooKeeper ZKTrustManager
At a glance
- Published
- Updated
- CVE
- CVE-2026-24281
- Aliases
- BIT-zookeeper-2026-24281
- CVSS_V3
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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.
Affected packages
| Package | Versions |
|---|---|
| Maven · org.apache.zookeeper:zookeeper | introduced 3.8.0, fixed 3.8.6 |
| Maven · org.apache.zookeeper:zookeeper | introduced 3.9.0, fixed 3.9.5 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-24281 ADVISORY
- https://github.com/apache/zookeeper/commit/66c4efecdda1302d9cfb3af9eedb122b74452bf3 WEB
- https://github.com/apache/zookeeper PACKAGE
- https://issues.apache.org/jira/browse/ZOOKEEPER-4986 WEB
- https://lists.apache.org/thread/088ddsbrzhd5lxzbqf5n24yg0mwh9jt2 WEB
- http://www.openwall.com/lists/oss-security/2026/03/07/4 WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |