The Bootstrap Multi-language Responsive Portfolio plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 1.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfilteredhtml has been disabled.

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Bootstrap allows Cross-Site Scripting (XSS).This issue affects Bootstrap: from 3.4.1 before 4.0.0.

An issue was discovered in post.php in bootstrap-multiselect (aka Bootstrap Multiselect) 1.1.2. A PHP script in the source code echoes arbitrary POST data. If a developer adopts this structure wholesale in a live application, it could create a Reflective Cross-Site Scripting (XSS) vulnerability exploitable through Cross-Site Request Forgery (CSRF).

An XSS issue was discovered in the Bootstrap 5 Lite theme before 1.x-1.0.3 for Backdrop CMS. It doesn't sufficiently sanitize certain class names.

The Bootstrap Ultimate theme for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 1.4.9 via the path parameter. This makes it possible for unauthenticated attackers to include PHP files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where PHP files can be uploaded and included. If php://filter is enabled on the server, this issue may directly lead to Remote Code Execution.