Vulnerability · Published Jul 28, 2026 · Assigned by Wordfence
CVE-2026-16774WPBot <= 8.5.9 - Missing Authorization to Unauthenticated Email Relay via wpcs_send_email AJAX Action
Medium 5.3
In plain English
A medium-severity missing authorization in WPBot – AI ChatBot for Live Support, Lead Generation, AI Services from quantumcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| quantumcloud | WPBot – AI ChatBot for Live Support, Lead Generation, AI Services | 0 – through 8.5.9 |
Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/3cc6aa06-ab2a-4d5c-bbbe-4c19722ccc53?source=cve
- https://plugins.trac.wordpress.org/browser/chatbot/tags/8.5.9/includes/chat-sessions/wpbot-chat-sessions.php#L494
- 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#L478
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3621386%40chatbot&new=3621386%40chatbot