CVE-2025-11517 Overview
CVE-2025-11517 is an authorization bypass vulnerability affecting the Event Tickets and Registration plugin for WordPress. This vulnerability allows unauthenticated attackers to obtain paid event tickets without completing the payment process, resulting in direct revenue loss for website operators.
The flaw exists in the /wp-json/tribe/tickets/v1/commerce/free/order REST API endpoint, which fails to verify whether a ticket type is genuinely configured as free before processing the order. Attackers can exploit this endpoint to request any ticket type through the free order workflow, effectively bypassing all payment requirements.
Critical Impact
Unauthenticated attackers can obtain paid tickets without payment, causing significant revenue loss for event organizers and undermining the integrity of ticketing systems.
Affected Products
- Event Tickets and Registration plugin for WordPress versions up to and including 5.26.5
Discovery Timeline
- 2025-10-18 - CVE-2025-11517 published to NVD
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2025-11517
Vulnerability Analysis
This vulnerability is classified under CWE-639 (Authorization Bypass Through User-Controlled Key), which occurs when an application uses user-controllable data to determine authorization without properly validating that the user should have access to the requested resource.
In this case, the Event Tickets plugin exposes a REST API endpoint designed specifically for processing free ticket orders. However, the endpoint accepts ticket IDs as parameters without validating whether those tickets are actually configured as free. This architectural flaw allows attackers to submit requests for any ticket type—including premium and paid tickets—through the free order processing path.
The vulnerability is particularly dangerous because it requires no authentication. Any remote attacker with knowledge of the endpoint can craft malicious requests to obtain tickets without paying.
Root Cause
The root cause lies in insufficient server-side validation within the Order_Endpoint.php file of the Free gateway module. The endpoint processes order requests without cross-referencing the ticket's configured price or payment requirements. This missing validation check allows the endpoint to fulfill orders for tickets that should require payment, treating all submitted tickets as if they were genuinely free.
Attack Vector
The attack is network-based and requires no authentication or user interaction. An attacker can directly access the vulnerable REST API endpoint and submit crafted HTTP requests containing ticket IDs for paid events.
The exploitation flow involves:
- Identifying a WordPress site using the vulnerable Event Tickets plugin
- Enumerating available ticket IDs (often predictable or exposed through event listings)
- Sending a POST request to /wp-json/tribe/tickets/v1/commerce/free/order with the desired paid ticket ID
- Receiving a valid ticket confirmation without payment processing
The attack can be automated to bulk-acquire tickets, potentially devastating event revenue and availability.
Detection Methods for CVE-2025-11517
Indicators of Compromise
- Unusual volume of requests to /wp-json/tribe/tickets/v1/commerce/free/order endpoint
- Ticket orders being created without corresponding payment transaction records
- Revenue discrepancies between tickets issued and payments received
- Multiple orders from the same IP address or user agent in rapid succession
Detection Strategies
- Implement web application firewall (WAF) rules to monitor and rate-limit requests to the free order endpoint
- Configure logging for all REST API calls to the Tribe Tickets commerce endpoints
- Set up alerts for ticket issuance events that lack associated payment confirmations
- Cross-reference ticket creation logs with payment gateway transaction logs
Monitoring Recommendations
- Enable verbose logging on WordPress REST API endpoints related to Event Tickets
- Monitor server access logs for patterns indicating endpoint enumeration or abuse
- Implement anomaly detection for unusual ticket ordering patterns
- Regularly audit ticket sales reports against financial records to identify discrepancies
How to Mitigate CVE-2025-11517
Immediate Actions Required
- Update the Event Tickets and Registration plugin to version 5.26.6 or later immediately
- Audit recent ticket orders to identify any potentially fraudulent free ticket acquisitions
- Temporarily disable the free ticket ordering endpoint if updates cannot be applied immediately
- Review and reconcile all ticket sales against payment records
Patch Information
The vulnerability has been addressed in Event Tickets and Registration plugin version 5.26.6. The fix modifies the Order_Endpoint.php file within the Free gateway module to properly validate that submitted tickets are genuinely configured as free before processing the order.
For technical details on the specific code changes, refer to the WordPress Plugin Change Log. Additional vulnerability information is available in the Wordfence Vulnerability Report.
Workarounds
- Implement WAF rules to block or challenge requests to the /wp-json/tribe/tickets/v1/commerce/free/order endpoint until patching is complete
- If no free tickets are offered, consider disabling the free ticket gateway entirely through plugin settings
- Add server-level access controls to restrict API endpoint access to trusted IP ranges where feasible
- Monitor and manually review all ticket orders processed through the free endpoint
# Example .htaccess rule to block access to vulnerable endpoint (temporary workaround)
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_URI} ^/wp-json/tribe/tickets/v1/commerce/free/order [NC]
RewriteRule ^(.*)$ - [F,L]
</IfModule>
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
