v4.2.0-M1

⭐ New Features

• Conflict when observability enabled and mixed batch and non-batch listeners #3947

🐞 Bug Fixes

• CVE-2026-59317: Harden retry_topic-original-timestamp and backoff timestamp header … #4578
• CVE-2026-59278: Normalize and restrict certain java.net types in header type mapping #4577
• Fix generateAntoraYml after version catalog migration #4559
• Fix tx offset lag when marker batch is separate #4553
• CommonDelegatingErrorHandler does not delegate onPartitionsAssigned(), causing silent record loss during retry #4545
• Backoff breaks recovery on batching listener container in multi partition environment #4371

📔 Documentation

• Fix typo in ConsumerProperties#setAuthExceptionRetryInterval javadoc #4556
• Update broken crosss reference in change-history.adoc #4544

🔨 Dependency Upgrades

• Bump org.junit:junit-bom from 6.1.2 to 6.1.3 #4566
• Dependency updates for 4.2.0-SNAPSHOT #4550

❤️ Contributors

Thank you to all the contributors who worked on this release:

@cppwfs, @ngocnhan-tran1996, @sobychacko, and @wolfpeyton