NATS v2.12.10

This maintenance release focuses on hardening the JetStream consensus layer and fixing critical protocol edge cases. It addresses potential data corruption in WebSockets and JetStream ACKs, stabilizes Raft peer tracking during stalls, and optimizes CPU usage for streams with high subject cardinality. Monitoring for leaf-node environments is also improved.

Protocol and Buffer Corruption Protection — Eliminates critical risks of protocol corruption in JetStream acknowledgments and WebSocket communications, ensuring high-performance messaging remains reliable without data integrity issues.

JetStream Cluster Stability and Quorum Fixes — Resolves edge-case Raft and quorum calculation bugs that could lead to cluster instability when nodes stall or when gateway URLs resolve to multiple IPs.

CPU Optimization for High-Subject Streams — Limits unoptimized block skip checks on streams with massive subject counts, preventing CPU spikes and ensuring resource efficiency for high-cardinality data sets.

Storage and Scale-Down Consistency Improvements — Ensures consistent behavior during scale-down operations and purge requests, making JetStream management more predictable across different storage types and consumer configurations.

Enhanced Client Identity in Authentication API — Provides developers with better visibility into client identities within custom authentication plugins, facilitating more granular access control.