CVE-2026-9626

Description

The JSON API User plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'content' parameter of the post_comment API endpoint in versions up to, and including, 4.1.0 This is due to insufficient input sanitization in the post_comment() function, which passes the attacker-controlled comment_content value directly to wp_insert_comment() without applying any HTML sanitization, and additionally allows the caller to set comment_approved=1 to self-approve the comment and bypass moderation. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

References

• https://plugins.trac.wordpress.org/browser/json-api-user/tags/4.1.0/controllers/User.php#L1007
• https://plugins.trac.wordpress.org/browser/json-api-user/tags/4.1.0/controllers/User.php#L979
• https://plugins.trac.wordpress.org/browser/json-api-user/tags/4.1.0/controllers/User.php#L995
• https://plugins.trac.wordpress.org/changeset/3576431/json-api-user/trunk/controllers/User.php
• https://plugins.trac.wordpress.org/changeset?old_path=%2Fjson-api-user/tags/4.1.0&new_path=%2Fjson-api-user/tags/4.1.2