Asana Math superscript overlaps parenthesis

I recently stumbled upon a bad superscript rendering with the Asana fonts. The following example should reproduce this.

    <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
      <msup>
        <mrow>
          <mo>(</mo>
          <munderover>
            <mo>&#x2211;<!-- ∑ --></mo>
            <mrow class="MJX-TeXAtom-ORD">
              <mi>k</mi>
              <mo>=</mo>
              <mn>1</mn>
            </mrow>
            <mi>n</mi>
          </munderover>
          <msub>
            <mi>a</mi>
            <mi>k</mi>
          </msub>
          <msub>
            <mi>b</mi>
            <mi>k</mi>
          </msub>
          <mo>)</mo>
        </mrow>
        <mrow class="MJX-TeXAtom-ORD">
          <mspace width="negativethinmathspace" />
          <mspace width="negativethinmathspace" />
          <mn>2</mn>
        </mrow>
      </msup>
    </math>