# NATS v2.15.1

> Networking & Messaging · 2026-10-09

A maintenance release focused on correctness and performance, with a legacy gateway behavior removed and new limits and validations that may affect existing configurations. It also includes fixes across authentication, account and subscription handling, configuration reloads, clustering, storage, consumers, and client operations.

## Check if affected
- **[security]** `auth_users` auth callout bypass issues corrected
  - Applies if you configure `auth_users`.
  - Issues with the auth callout `auth_users` bypass have been fixed.
- **[breaking]** The `max_ha_assets` limit, enforced consistently
  - Applies if you configure `max_ha_assets`.
  - The metalayer leader now enforces the `max_ha_assets` limit consistently during stream and consumer placement, scaling, and moves.
- **[breaking]** The legacy `$GR.` reply prefix, removed
  - Applies if you use the legacy `$GR.` reply prefix.
  - Support for sending and handling the legacy `$GR.` reply prefix used by servers before v2.1.2 has been removed.
- **[breaking]** Remote proxy options rejected without a proxy URL
  - Applies if you configure Remote proxy options and do not specify a proxy URL.
  - Remote proxy options are now rejected when no proxy URL is specified.
- **[breaking]** The legacy `$GR.` reply prefix reserved on client ingress
  - Applies if client ingress is in use.
  - The legacy `$GR.` reply prefix is now reserved on client ingress, preventing clients from publishing to gateway reply subjects that use the prefix.

## Other recorded changes
- 60 (defect_corrected 43, value_changed 15, added 1, constraint_changed 1)

[Full analysis](https://ratatosk.io/en/releases/nats/v2.15.1)

[Original release notes](https://github.com/nats-io/nats-server/releases/tag/v2.15.1)