Improper Validation of Certificate with Host Mismatch Affecting zookeeper-3.9 package, versions <3.9.6-r0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-MINIMOSLATEST-ZOOKEEPER39-19958008
- published20 Sept 2026
- disclosed16 Sept 2026
Introduced: 16 Sep 2026
NewCVE-2026-59969 (opens in a new tab)How to fix?
Upgrade Minimos:latest zookeeper-3.9 to version 3.9.6-r0 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream zookeeper-3.9 package and not the zookeeper-3.9 package as distributed by Minimos.
See How to fix? for Minimos:latest relevant fixed versions and status.
Apache ZooKeeper quorum TLS fails to enforce peer hostname verification in FIPS-mode deployments. When sslQuorum=true, zookeeper.fips-mode=true, ssl.quorum.hostnameVerification=true, and ssl.quorum.clientHostnameVerification=true are enabled, the Java SSLSocket quorum path accepts a CA-trusted peer certificate whose SAN does not match the connected host. A malicious or misissued peer certificate can therefore join quorum traffic, participate in leader election, and enter replication flows.
Users are recommended to upgrade to version 3.8.7 or 3.9.6, which fixes the issue.
References
- https://www.cve.org/CVERecord?id=CVE-2026-59969
- https://github.com/advisories/GHSA-4pv3-cr63-m4ph
- https://osv.dev/vulnerability/MINI-hj65-6wwj-f9qq
- https://osv.dev/vulnerability/CVE-2026-59969
- https://lists.apache.org/thread/qf9kwsgtgbgtvwls6f41281846xg0rss
- http://www.openwall.com/lists/oss-security/2026/09/15/4