Apache Cassandra Release Notes¶

Highlights from current and recent Apache Cassandra releases. For complete patch-level changes, see the upstream CHANGES.txt files linked at the bottom of each version stream.

5.0.x¶

Cassandra 5.0.8 (April 2026) - Current Release¶

Backport Automated Repair Inside Cassandra for CEP-37 (CASSANDRA-21138)
Update cassandra-stress to support TLS 1.3 by default by auto-negotiation (CASSANDRA-21007)
Ensure schema created before 2.1 without tableId in folder name can be loaded in SnapshotLoader (CASSANDRA-21173)
Harden data resurrection startup check with atomic heartbeat file write with fallback (CASSANDRA-21290) — backported from 4.1
Improved observability in AutoRepair to report both expected vs. actual repair bytes and expected vs. actual keyspaces (CASSANDRA-20581) — backported from 6.0
Stop repair scheduler if two major versions are detected (CASSANDRA-20048) — backported from 6.0
AutoRepair: Safeguard Full repair against disk protection (CASSANDRA-20045) — backported from 6.0
Stop AutoRepair monitoring thread upon Cassandra shutdown (CASSANDRA-20623) — backported from 6.0
Fix race condition in auto-repair scheduler (CASSANDRA-20265) — backported from 6.0
Implement minimum repair task duration setting for auto-repair scheduler (CASSANDRA-20160) — backported from 6.0
Implement preview_repaired auto-repair type (CASSANDRA-20046) — backported from 6.0
Automated Repair Inside Cassandra for CEP-37 (CASSANDRA-19918) — backported from 6.0

Cassandra 5.0.7 (March 2026)¶

Refactor SAI ANN query execution to use score ordered iterators for correctness and speed (CASSANDRA-20086)
Fix ConcurrentModificationException in compaction garbagecollect (CASSANDRA-21065)
Dynamically skip sharding L0 when SAI Vector index present (CASSANDRA-19661)
Automatically disable zero-copy streaming for legacy sstables with old bloom filter format (CASSANDRA-21092)
Correctly calculate default for FailureDetector max interval (CASSANDRA-21025)
Rate limit password changes (CASSANDRA-21202)
Obsolete expired SSTables before compaction starts (CASSANDRA-19776)
Switch lz4-java to at.yawk.lz4 version due to CVE (CASSANDRA-21052)
Fix memory leak in BufferPoolAllocator when capacity needs to be extended (CASSANDRA-20753)

For previous 5.0.x patch release details, see the Apache Cassandra changelog.

Cassandra 5.0.0 (September 2024) - Major Release¶

Storage-Attached Indexes (SAI) (CEP-7) - Efficient secondary indexing (experimental in 4.0+, production-ready in 5.0)
Vector data type and search (CEP-30) - Approximate nearest neighbor searching via SAI
Unified Compaction Strategy (UCS) (CEP-26) - Adaptive compaction replacing multiple strategies
Trie memtables (CEP-19) - Trie-based in-memory data structures
Trie SSTables (CEP-25) - Trie-indexed SSTable format
Dynamic Data Masking (CEP-20) - Selective redaction of sensitive data at query time
Java 17 support - recommended for Cassandra 5.0
TTL and writetime on collections/UDTs - Extended metadata for complex types
CIDR-based authorizer (CEP-33) - Network-based access control
New math functions: abs, exp, log, log10, round

4.1.x¶

Cassandra 4.1.11 (March 2026) - Current 4.1 Release¶

Disk usage guardrail cannot be disabled when failure threshold is reached (CASSANDRA-21057)
ReadCommandController should close fast to avoid deadlock when building secondary index (CASSANDRA-19564)
Redact security-sensitive information in system_views.settings (CASSANDRA-20856)
Rate limit password changes (CASSANDRA-21202)
Obsolete expired SSTables before compaction starts (CASSANDRA-19776)
Switch lz4-java to at.yawk.lz4 version due to CVE (CASSANDRA-21052)
Fix memory leak in BufferPoolAllocator when capacity needs to be extended (CASSANDRA-20753)
Add option to disable cqlsh history (CASSANDRA-21180)

Cassandra 4.1.0 (December 2022) - Major Release¶

Paxos v2 - Enhanced lightweight transaction protocol
Guardrails - Operational safety boundaries and limits
Partition denylist - Block access to problematic partitions
Top partition tracking - Per-table monitoring of hot partitions
Native transport rate limiting - Request throughput controls
Client-side password hashing - Enhanced authentication security
Pluggable memtables - Custom memtable implementations

For previous 4.1.x patch release details, see the Apache Cassandra changelog.

4.0.x¶

Cassandra 4.0.20 (March 2026) - Current 4.0 Release¶

Rate limit password changes (CASSANDRA-21202)
Obsolete expired SSTables before compaction starts (CASSANDRA-19776)
Switch lz4-java to at.yawk.lz4 version due to CVE (CASSANDRA-21052)
Fix memory leak in BufferPoolAllocator when capacity needs to be extended (CASSANDRA-20753)
Fix cleanup of old incremental repair sessions on token range changes or table deletion (CASSANDRA-20877)
ArrayIndexOutOfBoundsException with repaired data tracking and counters (CASSANDRA-20871)
Add option to disable cqlsh history (CASSANDRA-21180)
Restrict BytesType compatibility to scalar types only (CASSANDRA-20982)

Cassandra 4.0.0 (July 2021) - Major Release¶

Virtual tables - System information via CQL queries
Audit logging - Comprehensive query audit trail
Full query logging - Capture all queries for replay
Incremental repair improvements - More efficient anti-entropy
Zero-copy streaming - Faster data transfer between nodes
Java 11 support - Modern JVM compatibility

For previous 4.0.x patch release details, see the Apache Cassandra changelog.

Version Compatibility¶

Version	Release Date	End of Support	Status
5.0.x	September 2024	Until 5.3.0 release	Current
4.1.x	December 2022	Until 5.2.0 release	Supported
4.0.x	July 2021	Until 5.1.0 release	Supported
3.11.x	June 2017	Unmaintained	Legacy

Upgrade Path

Direct upgrades skipping major versions are not supported. To upgrade from 3.11.x to 5.0.x:

Upgrade 3.11.x → 4.0.x
Upgrade 4.0.x → 4.1.x
Upgrade 4.1.x → 5.0.x