# NumPy 1.16.3 Release Notes

The NumPy 1.16.3 release fixes bugs reported against the 1.16.2 release, and also backports several enhancements from master that seem appropriate for a release series that is the last to support Python 2.7. The wheels on PyPI are linked with OpenBLAS v0.3.4+, which should fix the known threading issues found in previous OpenBLAS versions.

Downstream developers building this release should use Cython >= 0.29.2 and, if using OpenBLAS, OpenBLAS > v0.3.4.

The most noticeable change in this release is that unpickling object arrays when loading `*.npy` or `*.npz` files now requires an explicit opt-in. This backwards incompatible change was made in response to CVE-2019-6446.

## Compatibility notes

### Unpickling while loading requires explicit opt-in

The functions `np.load`, and `np.lib.format.read_array` take an allow_pickle keyword which now defaults to `False` in response to CVE-2019-6446.

## Improvements

### Covariance in random.mvnormal cast to double

This should make the tolerance used when checking the singular values of the covariance matrix more meaningful.

## Changes

### `__array_interface__` offset now works as documented

The interface may use an `offset` value that was previously mistakenly ignored.