Improper Validation of Certificate with Host Mismatch Affecting org.apache.zookeeper:zookeeper package, versions [3.8.0, 3.8.7)[3.9.0, 3.9.6)
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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- published27 Sept 2026
- disclosed16 Sept 2026
- creditErichen <ch...@ict.ac.cn>
Introduced: 16 Sep 2026
NewCVE-2026-59969 (opens in a new tab)How to fix?
Upgrade org.apache.zookeeper:zookeeper to version 3.8.7, 3.9.6 or higher.
Overview
org.apache.zookeeper:zookeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services.
Affected versions of this package are vulnerable to Improper Validation of Certificate with Host Mismatch in the quorum process when FIPS mode is enabled and both sslQuorum, zookeeper.fips-mode, ssl.quorum.hostnameVerification, and ssl.quorum.clientHostnameVerification are set to true. An attacker can intercept or impersonate quorum peers by presenting a CA-trusted certificate with a mismatched Subject Alternative Name (SAN), allowing unauthorized participation in quorum traffic, leader election, and replication flows.
Note: This is only exploitable if all the mentioned configuration options are enabled simultaneously.