Dask 2026.7.0 was published on July 6, 2026, with expression protocol work at the center of the release. For data engineers running Dask in dataframe ETL jobs, the main change is support for composite expressions through __dask_exprs__, plus a related fix that avoids graph materialization in is_dask_collection for expression wrappers. This release is not marked as a prerelease.

Dask 2026.6.0 shipped on June 11, 2026 as a stable release. The headline fix for data pipelines is a DataFrame.merge bug that dropped rows when the graph had exactly 128 or 129 partitions, a failure mode that is easy to miss until you audit output counts.