A vulnerability that allows unauthenticated attacker to inject JavaScript code, XSS or cross-site scripting, in WordPress commenting system. The comments are stored in the table WP_comments, precisily in the column comment_content with type text that has a maximum size of 65535 bytes (or 64 kilobytes) When this limit is reached the database truncates and inserts the information, resulting in malformed HTML generated on the page. This is specially dangerous if the administrator of the site is logged in his administrative account, because this permits change of password, and so on.”]
Source: https://informationsecuritybuzz.com/articles/wordpress-comments-in-trouble/