- The `export` query parameter (inconsistently supported by API resources and deprecated in v1.14) is fully removed.  Requests setting this query parameter will now receive a 400 status response. ([#98312](https://github.com/kubernetes/kubernetes/pull/98312), [@deads2k](https://github.com/deads2k)) [SIG API Machinery, Auth and Testing]

* Audit logs might impact the API server performance and the latency of large request and response calls. The issue is observed under the following conditions: if `AdvancedAuditing` feature gate is enabled, which is the default case, if audit logging uses the log backend in JSON format, or if the audit policy records large API calls for requests or responses.

For more information, see [#51899](https://github.com/kubernetes/kubernetes/issues/51899).

* Fixes a regression proxying responses from aggregated API servers which could cause watch requests to hang until the first event was received ([#75887](https://github.com/kubernetes/kubernetes/pull/75887), [@liggitt](https://github.com/liggitt))

* The `emptyDir.sizeLimit` field is now correctly omitted from API requests and responses when unset. ([#50163](https://github.com/kubernetes/kubernetes/pull/50163), [@jingxu97](https://github.com/jingxu97))