Add what's new for confusion integer overflow fix
@@ -400,6 +400,10 @@ Bug fixes
reused the same estimator for each parameter value.
:issue:`7365` by :user:`Aleksandr Sandrovskii <Sundrique>`.
+ - Fixed an integer overflow bug in :func:`metrics.confusion_matrix` and
+ hence :func:`metrics.cohen_kappa_score`. :issue:`8354`, :issue:`7929`
+ by `Joel Nothman`_ and :user:`Jon Crall <Erotemic>`.
+
API changes summary
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