CVE-2026-11766

The Ultimate Member WordPress plugin before 2.13.1 does not escape a value derived from user supplied profile names before outputting it in the page title, and decodes HTML entities in it after its own sanitisation has already run, allowing unauthenticated attackers who register an account to store JavaScript that will execute when any visitor, including an administrator, views their profile.

The Ultimate Member WordPress plugin before version 2.13.0 does not check whether a comment has been approved or whether the profile it belongs to is private before returning profile activity to unauthenticated visitors. This allows reading the content of comments still awaiting moderation.

The Ultimate Member plugin for WordPress up to version 2.12.1 is vulnerable to Stored Cross-Site Scripting via Textarea Profile Field with HTML Support (DOM Gadget via id Attribute). Insufficient input sanitization and output escaping allow authenticated attackers with subscriber-level access and above to inject arbitrary web scripts that execute when a user accesses an injected page.

The Ultimate Member WordPress plugin before 2.12.1 does not filter administrator-level capabilities from the roles it makes selectable on its registration forms, and its post-registration safeguard against elevated accounts is disabled by default, allowing unauthenticated users to register with a site-defined role that carries administrator capabilities and gain administrative access, when such a role exists and a role-selection field is present on a published registration form.

The Ultimate Member plugin for WordPress is vulnerable to blind SQL injection via the search parameter in all versions up to and including 2.10.1 due to insufficient escaping and lack of query preparation. This allows unauthenticated attackers to append additional SQL queries and extract sensitive information from the database.

The Ultimate Member plugin for WordPress is vulnerable to stored XSS via the 'about_me' parameter in versions up to 2.11.4 inclusive due to insufficient input sanitization and output escaping.

The Ultimate Member plugin for WordPress up to version 2.11.1 is vulnerable to stored cross-site scripting (XSS) via the user description field due to insufficient input sanitization and output escaping. Authenticated attackers with subscriber-level access or higher can inject arbitrary scripts that execute when a user visits an affected page. The vulnerability is exploitable only when "HTML support for user description" is enabled in Ultimate Member settings.