CVE-2026-16774

Description

The Chatbot plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 8.5.9 via the wpcs_send_email() AJAX handler. This is due to the wpcs_send_email() function being registered on both wp_ajax_wpcs_send_email and wp_ajax_nopriv_wpcs_send_email with no nonce verification, capability check, or rate limiting, while forwarding attacker-controlled recipient, subject, and body directly to wp_mail(). This makes it possible for unauthenticated attackers to send arbitrary emails to any recipient from the site's domain, enabling spam, phishing, and abuse that can lead to the site's IP/domain being blacklisted.

References

• https://plugins.trac.wordpress.org/browser/chatbot/tags/8.5.9/includes/chat-sessions/wpbot-chat-sessions.php#L478
• https://plugins.trac.wordpress.org/browser/chatbot/tags/8.5.9/includes/chat-sessions/wpbot-chat-sessions.php#L483
• https://plugins.trac.wordpress.org/browser/chatbot/tags/8.5.9/includes/chat-sessions/wpbot-chat-sessions.php#L494
• https://plugins.trac.wordpress.org/changeset?reponame=&old=3621386%40chatbot&new=3621386%40chatbot
• https://www.wordfence.com/threat-intel/vulnerabilities/id/3cc6aa06-ab2a-4d5c-bbbe-4c19722ccc53?source=cve