Hyper-Converged Database (HCD) release notes
Hyper-Converged Database (HCD) is compatible with Apache Cassandra® 4.0 and adds additional production-certified changes. HCD includes the following innovations:
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Storage Attached Indexes (SAI) for advanced database indexes
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Data API for a simple JSON document-oriented interface to data. For more details on the Data API, see Get started with the Data API.
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Trie based data structures for significantly improved performance
Here are the features, enhancements, and updates per HCD version.
Version 1.2.6
This version was released on May 11, 2026 and includes the following items:
New features and enhancements
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Updated default Guardrail configurations. JVM Heap settings are now automatically optimized according to the server’s number of cores and physical memory. (HCD-198)
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Upgraded the security plugin library to include Apache Directory version 2.0.0.M27. (HCD-286)
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Added support for Python versions 3.12 and 3.13 and Python driver version 3.29. Removed support for Python version 2.7. (HCD-190)
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Upgraded
httpcore5-h2to version 5.4.0. (HCD-319) -
Upgraded the
logback-corelibrary to version 1.5.25. (HCD-261)
Fixed issues
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Fixed an issue with DSE 6.9 nodes when upgrading to HCD with encryption enabled. (HCD-241)
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Fixed an issue with concurrent repairs and compactions. (HCD-200)
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Fixed a race in prepared statements porting CASSANDRA-19703. (HCD-146)
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Upgraded the Docker Management API version to 0.1.116 to fix broken metrics endpoints. (HCD-324)
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Fixed CQLSH
DESCRIBEcommand failures. (HCD-339)
Security fixes
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Upgraded Netty to version 4.1.132.Final. (HCD-321), CVE-2026-33871, CVE-2026-33870
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Upgraded BouncyCastle to version 1.84. (HCD-332), CVE-2025-14813, CVE-2026-0636, CVE-2026-5588, CVE-2026-5598
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Upgraded httpclient5 to version 5.6.1. (HCD-333), CVE-2026-40542
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Upgraded httpcore5-h2 to version 5.4.0. (HCD-319), CVE-2025-8671
Version 1.2.5
This version was released on January 26, 2026 and includes the following items:
New features and enhancements
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Upgraded
commons-codecto version 1.20.0. (HCD-262) -
Upgraded Bouncy Castle to version 1.83. (HCD-263)
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Added an option to skip exception logging on invalid legacy protocol magic exceptions. (HCD-247)
Security fixes
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Upgraded Netty to version 4.1.130 and BoringSSL to version 2.0.74. (HCD-258), (CVE-2025-67735)
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Upgraded
jackson-dataformat-msgpackto version 0.9.11 andjacksonto version 2.18.4. (HCD-259), (CVE-2026-21452) -
Upgraded the JDK for RedHat UBI images to version 11.0.29. (HCD-260), (CVE-2025-53066)
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Upgraded logback to version 1.5.25. (HCD-261), (CVE-2024-12798), (CVE-2025-11226), (CVE-2026-1225), (CVE-2024-12801)
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Upgraded the lz4-java library to version 1.10.2. (HCD-264), (CVE-2025-12183)
For a complete list of CVEs fixed in this release, see the IBM Security Bulletin for HCD.
Version 1.2.4
This version was released on November 5, 2025 and includes the following items:
New features and enhancements
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Upgraded Bouncy Castle to version 1.82. (HCD-207)
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Upgraded Guava to 33.5.0. (HCD-211), (CVE-2020-8908), (CVE-2023-2976), (CVE-2025-59419)
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Upgraded Netty to 4.1.128.Final. (HCD-205), (CVE-2025-59419)
Version 1.2.3
Version 1.2.3 is the first public release of HCD 1.2. This version was released on August 1, 2025 and includes the following items:
New features and enhancements
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Added the following security updates:
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Lightweight Directory Access Protocol (LDAP) authentication support (HCD-2)
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Role-based access control (RBAC) support (HCD-3)
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Encryption key management (HCD-4)
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Transparent Data Encryption (TDE) support (DSP-23529)
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OpenID Connect (OIDC) authentication support (DSP-24578)
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For more information, see the Security section.
