CVE-2026-109998: Mang Board <= 2.4.3 - Unauthenticated Stored Cross-Site Scripting via 'content' Parameter via content_reply AJAX
The Mang Board plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'content' parameter in all versions up to, and including, 2.4.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is exploitable because the wpajaxnoprivmbtemplate endpoint is publicly accessible without authentication, nonce verification is not enforced for the contentreply mode, and admin-ajax.php responds with Content-Type: text/html, causing browsers to execute injected tags embedded in the JSON response body.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue, and what access is required?
Any unauthenticated remote attacker can exploit it. The affected AJAX endpoint is publicly accessible, and the content_reply mode does not enforce nonce verification.
Are default WordPress installations using the plugin exposed?
Sites using an affected Mang Board version are exposed through the publicly accessible wp_ajax_nopriv_mb_template endpoint. No authenticated WordPress account is required for exploitation.
What happens when the malicious content is viewed?
Injected scripts execute in the browser when a user accesses the injected page. The endpoint returns text/html, which can cause browsers to execute injected tags contained in the JSON response body.
Which versions are affected?
All Mang Board versions up to and including 2.4.3 are affected.