WP Popups < 2.1.5.1 - Contributor+ Stored XSS

The plugin does not properly escape the href attribute of its spu-facebook-page shortcode before outputting it back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks. This is due to an insufficient fix of CVE-2023-24003

PoC

[spu-facebook-page href=“javascript:alert(/XSS/)” name=“ClickMe!”] The XSS will be triggered when a user click on the ClickMe! link in the page where the shortcode is embed