detailed in <a href="/issue/61716">proposal #61716</a>. The most important changes are:
</p>

<ul>
<li>The <code>Read</code> method, deprecated in <code>math/rand</code>,
was not carried forward for <code>math/rand/v2</code>.
(It remains available in <code>math/rand</code>.)
The vast majority of calls to <code>Read</code> should use
<a href="/pkg/crypto/rand/#Read"><code>crypto/rand</code>’s <code>Read</code></a> instead.