comment_excerpt does not use htmlspecialchars

[gene91]

As a result, I will have to always use
echo htmlspecialchar(get_comment_excerpt())
if I don't want my blog goes wrong as there could be quotes in the comment.

[scribu]

You can add this single line into your theme's functions.php:

add_filter('comment_excerpt', 'esc_html');

[nacin]

I don't even see the use case for doing so. It's already kses'd.