CVE-2026-83537
Deferred Deferred - Pending Action

WP Express Checkout Order Completion Vulnerability

Publication date: 2026-09-09

Last updated on: 2026-09-09

Assigner: WPScan

Description
The WP Express Checkout WordPress plugin before 2.5.0 does not verify server-side that a payment was actually completed before marking an order as paid, allowing unauthenticated users to forge a completed order without paying.

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Meta Information

Published
2026-09-09
Last Modified
2026-09-09
Generated
2026-09-29
AI Q&A
2026-09-10
EPSS Evaluated
2026-09-27
NVD
CVE-2026-83537
EUVD
EUVD-2026-74723

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
wp_express_checkout wp_express_checkout to 2.5.0 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-345 The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

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Executive Summary

This vulnerability in the WP Express Checkout WordPress plugin before version 2.5.0 allows unauthenticated users to forge a completed order without actually paying. The plugin fails to verify server-side if a payment was completed before marking an order as paid.

Detection Guidance

Check the installed version of the WP Express Checkout plugin. If it is below 2.5.0, the system is vulnerable. Use commands like 'wp plugin list' in WordPress CLI or inspect the plugin files directly.

Impact Analysis

Attackers could exploit this to get free products or services by creating fake paid orders. This could lead to financial losses for the website owner and undermine trust in the payment system.

Compliance Impact

This vulnerability could lead to unauthorized transactions, potentially violating data integrity and financial compliance requirements under standards like GDPR and HIPAA. Unpaid orders marked as paid may result in improper financial record-keeping, which could conflict with audit and reporting obligations in these regulations.

Mitigation Strategies

Update the WP Express Checkout plugin to version 2.5.0 or later immediately. Disable the plugin temporarily if an update is not immediately possible. Monitor order statuses for suspicious activity.

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