v18.9.0

## Description

### Device Bound Session Credentials for App Access

Application access session cookies are now compatible with Google's Device Bound
Session Credentials, adding a layer of protection against session hijacking and
cookie theft.

### High-DPI support for Windows desktop sessions

Remote desktop sessions now support high-DPI mode, improving the clarity and
quality of the display rendering on supported displays.

### Sub-CA

Teleport now supports operating as a sub-CA of an external root for the Windows
Desktop and Database Client CAs. Subsequent releases will extend support for
other CAs.

### Other fixes and improvements

* Outdated agents joining via the legacy Auth HTTP endpoint now receive an explicit "client too old" error instead of a confusing 404. [#67532](https://github.com/gravitational/teleport/pull/67532)
* Rename --from/--to to --from-utc/--to-utc on `recordings search` to match the `recordings ls` flag naming convention. [#67502](https://github.com/gravitational/teleport/pull/67502)
* Improved performance and reduced resource usage of the auth service for clusters with large numbers of registered applications with per-session MFA enabled. [#67471](https://github.com/gravitational/teleport/pull/67471)
* Prevented ssh users from being able to cancel other users' remote port forwards. [#67442](https://github.com/gravitational/teleport/pull/67442)
* Improved application server resolution times for large number of applications. [#62585](https://github.com/gravitational/teleport/pull/62585)

## Download

Download the current and previous releases of Teleport at https://goteleport.com/download.

## Plugins

Download the current release of Teleport plugins from the links below.
* Slack [Linux amd64](https://cdn.teleport.dev/teleport-access-slack-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-access-slack-v18.9.0-linux-arm64-bin.tar.gz) 
* Mattermost [Linux amd64](https://cdn.teleport.dev/teleport-access-mattermost-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-access-mattermost-v18.9.0-linux-arm64-bin.tar.gz)
* Discord [Linux amd64](https://cdn.teleport.dev/teleport-access-discord-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-access-discord-v18.9.0-linux-arm64-bin.tar.gz)
* Terraform Provider [Linux amd64](https://cdn.teleport.dev/terraform-provider-teleport-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/terraform-provider-teleport-v18.9.0-linux-arm64-bin.tar.gz) | [macOS amd64](https://cdn.teleport.dev/terraform-provider-teleport-v18.9.0-darwin-amd64-bin.tar.gz) | [macOS arm64](https://cdn.teleport.dev/terraform-provider-teleport-v18.9.0-darwin-arm64-bin.tar.gz) | [macOS universal](https://cdn.teleport.dev/terraform-provider-teleport-v18.9.0-darwin-universal-bin.tar.gz)
* Event Handler [Linux amd64](https://cdn.teleport.dev/teleport-event-handler-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-event-handler-v18.9.0-linux-arm64-bin.tar.gz) | [macOS amd64](https://cdn.teleport.dev/teleport-event-handler-v18.9.0-darwin-amd64-bin.tar.gz)
* PagerDuty [Linux amd64](https://cdn.teleport.dev/teleport-access-pagerduty-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-access-pagerduty-v18.9.0-linux-arm64-bin.tar.gz)
* Jira [Linux amd64](https://cdn.teleport.dev/teleport-access-jira-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-access-jira-v18.9.0-linux-arm64-bin.tar.gz)
* Email [Linux amd64](https://cdn.teleport.dev/teleport-access-email-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-access-email-v18.9.0-linux-arm64-bin.tar.gz)
* Microsoft Teams [Linux amd64](https://cdn.teleport.dev/teleport-access-msteams-v18.9.0-linux-amd64-bin.tar.gz) | [Linux arm64](https://cdn.teleport.dev/teleport-access-msteams-v18.9.0-linux-arm64-bin.tar.gz)