安全：不安全的跨域链接

URLs that link to external websites using the target="_blank" attribute (to open in a new tab), without using rel="noopener" (or rel="noreferrer") at the same time. Using target="_blank" alone leaves those pages exposed to both security and performance issues for some legacy browsers, which are estimated to be below 5% of market share. Setting target="_blank" on <a> elements implicitly provides the same rel behavior as setting rel="noopener" which does not set window.opener for most modern browsers, such as Chrome, Safari, Firefox and Edge. The external links that contain the target="_blank" attribute by itself can be viewed in the 'outlinks' tab and 'target' column. They can be exported alongside the pages they are linked from via 'Bulk Export > Security > Unsafe Cross-Origin Links'.

How to fix: Consider the benefits of including the rel="noopener" link attribute on any links that contain the target="_blank" attribute to avoid security and performance issues for the users of legacy browsers that may visit the website.