The YMC Filter plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via the 'posttitle' parameter in all versions up to, and including, 3.12.19 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The autocomplete REST endpoint is registered with a permission callback that unconditionally returns true, meaning any site visitor — including unauthenticated users — can trigger the payload simply by typing in the YMC filter search box, while only Author-level access is required to store it.

Missing Authorization vulnerability in YMC Filter & Grids allows Accessing Functionality Not Properly Constrained by ACLs.This issue affects Filter & Grids: from n/a through 2.8.33.

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in YMC Filter & Grids allows Stored XSS.This issue affects Filter & Grids: from n/a through 2.9.2.