- Fix a panic when deleting an entry from /etc/hosts file ([#21019](https://github.com/docker/docker/pull/21019))
- Source the forwarded DNS queries from the container net namespace ([#21019](https://github.com/docker/docker/pull/21019))
- Fix to retain the network internal mode config for bridge networks on daemon reload ([#21780] (https://github.com/docker/docker/pull/21780))
- Fix to retain IPAM driver option configs on daemon reload ([#21914] (https://github.com/docker/docker/pull/21914))
### Plugins
- Fix a file descriptor leak that would occur every time plugins were enumerated ([#20686](https://github.com/docker/docker/pull/20686))
- Fix an issue where Authz plugin would corrupt the payload body when faced with a large amount of data ([#20602](https://github.com/docker/docker/pull/20602))
### Runtime
- Fix a panic that could occur when cleanup after a container started with invalid parameters ([#21716](https://github.com/docker/docker/pull/21716))
- Fix a race with event timers stopping early ([#21692](https://github.com/docker/docker/pull/21692))
- Fix race conditions in the layer store, potentially corrupting the map and crashing the process ([#21677](https://github.com/docker/docker/pull/21677))
- Un-deprecate auto-creation of host directories for mounts. This feature was marked deprecated in ([#21666](https://github.com/docker/docker/pull/21666))
Docker 1.9, but was decided to be too much of a backward-incompatible change, so it was decided to keep the feature.
+ It is now possible for containers to share the NET and IPC namespaces when `userns` is enabled ([#21383](https://github.com/docker/docker/pull/21383))
+ `docker inspect <image-id>` will now expose the rootfs layers ([#21370](https://github.com/docker/docker/pull/21370))
+ Docker Windows gained a minimal `top` implementation ([#21354](https://github.com/docker/docker/pull/21354))
* Docker learned to report the faulty exe when a container cannot be started due to its condition ([#21345](https://github.com/docker/docker/pull/21345))
* Docker with device mapper will now refuse to run if `udev sync` is not available ([#21097](https://github.com/docker/docker/pull/21097))
- Fix a bug where Docker would not validate the config file upon configuration reload ([#21089](https://github.com/docker/docker/pull/21089))
- Fix a hang that would happen on attach if initial start was to fail ([#21048](https://github.com/docker/docker/pull/21048))
- Fix an issue where registry service options in the daemon configuration file were not properly taken into account ([#21045](https://github.com/docker/docker/pull/21045))
- Fix a race between the exec and resize operations ([#21022](https://github.com/docker/docker/pull/21022))
- Fix an issue where nanoseconds were not correctly taken in account when filtering Docker events ([#21013](https://github.com/docker/docker/pull/21013))
- Fix the handling of Docker command when passed a 64 bytes id ([#21002](https://github.com/docker/docker/pull/21002))
* Docker will now return a `204` (i.e http.StatusNoContent) code when it successfully deleted a network ([#20977](https://github.com/docker/docker/pull/20977))
- Fix a bug where the daemon would wait indefinitely in case the process it was about to killed had already exited on its own ([#20967](https://github.com/docker/docker/pull/20967)
* The devmapper driver learned the `dm.min_free_space` option. If the mapped device free space reaches the passed value, new device creation will be prohibited. ([#20786](https://github.com/docker/docker/pull/20786))
+ Docker can now prevent processes in container to gain new privileges via the `--security-opt=no-new-privileges` flag ([#20727](https://github.com/docker/docker/pull/20727))
- Starting a container with the `--device` option will now correctly resolves symlinks ([#20684](https://github.com/docker/docker/pull/20684))
+ Docker now relies on [`containerd`](https://github.com/docker/containerd) and [`runc`](https://github.com/opencontainers/runc) to spawn containers. ([#20662](https://github.com/docker/docker/pull/20662))