The Woocommerce Custom Product Addons Pro plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 5.4.1 via the custom pricing formula eval() in the process_custom_formula() function within includes/process/price.php. This is due to insufficient sanitization and validation of user-submitted field values before passing them to PHP's eval() function. The sanitize_values() method strips HTML tags but does not escape single quotes or prevent PHP code injection. This makes it possible for unauthenticated attackers to execute arbitrary code on the server by submitting a crafted value to a WCPA text field configured with custom pricing formula (pricingType: "custom" with {this.value}).
CVE-2026-4001 is a critical severity with CVSS 9.8 Remote Code Execution issue affecting the Plugin Woocommerce Custom Product Addons Pro. It affects Versions up to 5.4.1 and is fixed in 5.4.2.
Use the related hub and response guides to connect this CVE-2026-4001 report with patch validation, scanner checks, and site hardening work.
Open the grouped hub for related CVEs, affected ranges, severity mix, and patch coverage.
Check access, XML-RPC exposure, backup readiness, and monitoring after patching.
Use containment, evidence capture, remediation, and validation steps when exploit risk is high.
CVE-2026-4001 is tracked for the Plugin Woocommerce Custom Product Addons Pro as critical severity with CVSS 9.8. The affected range is Versions up to 5.4.1. Update Woocommerce Custom Product Addons Pro to 5.4.2 or newer where that version is compatible with the site.
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This report has a CVE identifier, which makes it suitable for focused search and vulnerability triage workflows.
Affected version data gives operators a concrete comparison point against installed WordPress software.
A fixed version is present, so the page can answer update and remediation intent directly.
External references are available for source validation, advisory review, and incident notes.
Use these checks when converting this record into a patch ticket, incident note, or risk acceptance decision.
Inventory the installed Plugin package and compare its version with Versions up to 5.4.1.
Confirm Woocommerce Custom Product Addons Pro is updated to 5.4.2 or newer.
Review references and CVSS vector details for exploitability, authentication requirements, and exposure path.
After patching, re-run vulnerability monitoring and keep the related plugin or theme hub under review for follow-up CVEs.
| Software Type | Plugin |
|---|---|
| Software Slug |
woo-custom-product-addons-pro
View on wordpress.org
|
| CVE | CVE-2026-4001 |
| Patched Versions |
5.4.2
|
| Affected Versions |
Versions up to 5.4.1
|
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