# Unreleased Changes Friendly reminder: We have a [bug bounty program](https://hackerone.com/cosmos). ## vX.X Month, DD, YYYY Special thanks to external contributors on this release: ### BREAKING CHANGES - CLI/RPC/Config - [config] [\#7276](https://github.com/tendermint/tendermint/pull/7276) rpc: Add experimental config params to allow for subscription buffer size control (@thanethomson). - Apps - P2P Protocol - [p2p] [\#7265](https://github.com/tendermint/tendermint/pull/7265) Peer manager reduces peer score for each failed dial attempts for peers that have not successfully dialed. (@tychoish) - Go API - Blockchain Protocol ### FEATURES - [rpc] [\#7270](https://github.com/tendermint/tendermint/pull/7270) Add `header` and `header_by_hash` RPC Client queries. (@fedekunze) (@cmwaters) ### IMPROVEMENTS - [\#7338](https://github.com/tendermint/tendermint/pull/7338) pubsub: Performance improvements for the event query API (backport of #7319) (@creachadair) ### BUG FIXES - [\#7310](https://github.com/tendermint/tendermint/issues/7310) pubsub: Report a non-nil error when shutting down (fixes #7306).