Responsive Gallery Grid < 2.3.9 - Contributor+ Stored XSS

The plugin does not validate and escape some of its shortcode attributes before outputting them 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.

PoC

Note: In ids, please add the image attachment id. Exploit: [gallery ids=‘1’ class=‘" onmouseover=“alert(1)” style=“background:red;”’]