CVE-2026-16773: WPBot WordPress Plugin Info Disclosure

CVE-2026-16773 Overview

The WPBot – AI ChatBot for Live Support, Lead Generation, AI Services plugin for WordPress contains a sensitive information exposure vulnerability in all versions up to and including 8.5.9. The flaw resides in the wpbot_send_email_transcript_free function, which lacks proper access controls. Unauthenticated attackers can exfiltrate full chat transcripts and associated user personally identifiable information (PII) to an attacker-controlled email address. Exposed data includes names, email addresses, and phone numbers stored in the wpbot_user and wpbot_conversation database tables. The vulnerability is tracked as CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.

Critical Impact
Unauthenticated remote attackers can exfiltrate stored chat transcripts and user PII from affected WordPress sites without any user interaction.

Affected Products

WPBot – AI ChatBot for Live Support, Lead Generation, AI Services plugin for WordPress
All versions up to and including 8.5.9
WordPress sites using the vulnerable wpbot_send_email_transcript_free endpoint

Discovery Timeline

2026-07-28 - CVE-2026-16773 published to NVD
2026-07-28 - Last updated in NVD database

Technical Details for CVE-2026-16773

Vulnerability Analysis

The vulnerability affects the wpbot_send_email_transcript_free function within the WPBot plugin's chat session handling code. This function is designed to email chat transcripts, but it fails to verify the requester's identity or ownership of the requested transcript. Because the endpoint is exposed without authentication or capability checks, any remote user can invoke it. The attacker can supply a destination email address of their choosing, causing the server to send stored conversation data outbound. The impacted code paths reside in includes/chat-sessions/wpbot-chat-sessions.php, referenced at lines 690, 702, 707, and 746 of the 8.5.9 release, per the WordPress plugin trac reference.

Root Cause

The root cause is missing authorization and access-control validation on a sensitive AJAX-style endpoint. The handler reads records from the wpbot_user and wpbot_conversation tables and dispatches them to a caller-supplied email address. No nonce validation, capability check, or session-owner verification restricts who can trigger the transcript export.

Attack Vector

An unauthenticated attacker sends a crafted network request to the vulnerable endpoint on a WordPress site running WPBot. The attacker specifies a session or conversation identifier along with an attacker-controlled recipient email address. The server processes the request, retrieves the stored transcript and PII, and mails the data to the attacker. Exploitation requires no privileges and no user interaction. Detailed technical analysis is available from the Wordfence Vulnerability Analysis.

Detection Methods for CVE-2026-16773

Indicators of Compromise

Web server access logs containing requests to admin-ajax.php invoking the wpbot_send_email_transcript_free action from unauthenticated sessions.
Outbound SMTP messages from the WordPress host addressed to email domains not associated with legitimate users.
Unexpected reads or high-volume queries against the wpbot_user and wpbot_conversation tables.

Detection Strategies

Inspect HTTP request logs for POST or GET traffic referencing the wpbot_send_email_transcript_free action parameter.
Correlate transcript-export events with the authenticated user session state to identify anonymous invocations.
Alert on repeated calls to the endpoint originating from a single IP address within short time windows.

Monitoring Recommendations

Monitor WordPress mail queue and mail server logs for transcript emails sent to external, non-corporate domains.
Track database query patterns against wpbot_conversation for bulk reads outside administrator workflows.
Enable file integrity monitoring on the chatbot plugin directory to detect tampering or downgrade attempts.

How to Mitigate CVE-2026-16773

Immediate Actions Required

Update the WPBot – AI ChatBot plugin to a version newer than 8.5.9 that includes the fix committed in changeset 3621386.
Audit the wpbot_conversation and wpbot_user tables to inventory data that may have been exposed.
Notify affected users if PII exfiltration is confirmed, per applicable data-protection regulations.

Patch Information

The vendor addressed the issue in the WordPress plugin repository. The fix is published in changeset 3621386 on the plugin trac. Site owners should apply the update through the WordPress admin plugin manager or via WP-CLI. Details are available in the WordPress Chatbot Change Set.

Workarounds

Deactivate the WPBot plugin until the patched version can be installed.
Deploy a Web Application Firewall (WAF) rule that blocks unauthenticated requests targeting the wpbot_send_email_transcript_free action.
Restrict access to admin-ajax.php for the transcript action by IP allowlist at the reverse proxy layer.

bash

# Configuration example: update the plugin via WP-CLI
wp plugin update chatbot
wp plugin get chatbot --field=version