# Amazon EMR 7.4.0 - ZooKeeper release notes
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| Type | Description | 
| --- | --- | 
| Upgrade | Zookeeper version is upgraded to 3.9.2. | 
| Improvement | [ZOOKEEPER-4778](https://issues.apache.org/jira/browse/ZOOKEEPER-4778): Patch jetty, netty, and logback to remove high severity vulnerabilities. | 
| Improvement | [ZOOKEEPER-4799](https://issues.apache.org/jira/browse/ZOOKEEPER-4778): Fixes CVE-2024-23944. | 
| Bug Fix | [ZOOKEEPER-4415](https://issues.apache.org/jira/browse/ZOOKEEPER-4778): TLSv1.3 support is added. | 

## Amazon EMR 7.4.0 - ZooKeeper Features
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+ Clusters with in-transit encryption security configuration provided will have TLS enabled by default for Quorum communication and Zookeeper Admin Server. Additionally, TLS secure port is exposed at 2281 for client communication with Zookeeper.