Instaclustr for Apache Kafka® and Apache Kafka® Connect 4.1.2 Are Generally Available

April 8, 2026 | By Varun Ghai

 

We are pleased to announce that Apache Kafka® 4.1.2 is now Generally Available (GA) on the NetApp Instaclustr Managed Platform. 

Apache Kafka 4.1.2 is a patch (bug‑fix) release in the 4.1.x release line. It delivers important stability improvements, security updates, and bug fixes across brokers, controllers, and clients. Kafka 4.1.2 fixes 30 issues since the 4.1.1 release, making it a recommended upgrade for customers running earlier 4.1.x versions. Full details of the upstream changes are available in the official Apache Kafka release notes and release announcement. 

As with all GA releases on our platform, Kafka 4.1.2 has been validated against our operational, reliability, and support standards before being made available to customers. 

 

What’s New in Apache Kafka 4.1.2 

Kafka 4.1.2 focuses on reliability and security, with fixes spanning core broker behavior, controller logic, and client interactions. In addition to security upgrades and third‑party dependency updates addressing reported CVEs, this release includes a number of noteworthy improvements. Some of the higher priority rating ones are: 

Broker, Controller, and Metadata Stability Improvements 

  • KAFKA-19862 — Fixes a case where group coordinator loading can fail during concurrent log compaction, breaking metadata load from __consumer_offsets.  
  • KAFKA-19888 — Fixes coordinator histogram corruption leading to persistent write timeouts/consumer instability in Kafka 4.1.0+. 
  • KAFKA-19899 — Ensures a group epoch bump occurs when a member’s regex subscription changes from non‑empty to empty, avoiding inconsistent group state. 
  • KAFKA-20115 — Fixes a bug where the group coordinator fails to unload metadata when the broker is no longer leader/follower, which can leave JOIN_GROUP / SYNC_GROUP hanging. 

Client and Protocol Fixes 

  • KAFKA-19012 — Fixes a rare producer/client issue where messages can end up on the wrong topic. 
  • KAFKA-19994 — Fixes Kafka Streams where TaskManager may not close all tasks on task timeouts, leaving task directories locked.  
  • KAFKA-19960 — Fixes Kafka Streams where StateDirectory close can fail due to locked task directories, causing downstream failures (e.g., RocksDB lock issues). 
  • KAFKA-20002 — Fixes a Kafka Streams reset-by-duration bug that incorrectly hands an active task back to the state updater. 
  • KAFKA-20046 — Fixes the kafka-streams-scala artifact being compiled with Java 17 instead of Java 11, which can break Java 11 users with UnsupportedClassVersionError. 

Security and Dependency Updates 

  • KAFKA-20038 — Addresses CVE‑2025‑68161 in log4j-core (Socket Appender TLS hostname verification issue) by upgrading to a fixed version.  
  • KAFKA-19876 — Replaces the deprecated OpenJDK Docker base image used by Kafka images. 

 

Lifecycle Guidance and Upgrade Recommendations 

With the release of Kafka 4.1.2, we have reviewed and updated the lifecycle states of older Kafka versions in accordance with our published lifecycle policy. To ensure continued access to full support and SLAs, we recommend that customers: 

  • Run GA versions of Kafka and Kafka Connect wherever possible 
  • Upgrade Kafka and Kafka Connect clusters at least once per year to a current GA release 
  • Plan upgrades proactively, especially when running older patch versions 

Before upgrading production clusters, we strongly recommend validating Kafka 4.1.2 in a non‑production environment to confirm compatibility with your Kafka clients, connectors, and applications. 

Details of all Kafka versions currently supported on the Instaclustr Managed Platform are available in our documentation. 

 

Getting Started or Upgrading 

If you need any help spinning up a new Kafka cluster or upgrading existing managed Kafka clusters, please feel free to get in touch with us via our support website.