CVE-2026-19914

The Welcart e-Commerce plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 2.12.1 via deserialization of untrusted input in the Telecom EDY payment callback (usces_action_acting_transaction). Unauthenticated attackers can store arbitrary 'reserve' key/value pairs as order metadata during a public checkout, then invoke the callback with an attacker-chosen 'option' parameter to select and unserialize that metadata without any provider signature, source-address, transaction-identity or ownership check. A POP chain is present in the TCPDF library bundled with the plugin itself, so no additional plugin or theme is required. This makes it possible for unauthenticated attackers to delete arbitrary files on the server, including wp-config.php, which can lead to remote code execution when an attacker re-runs the WordPress installer against a database they control. Successful exploitation is contingent on an admin printing an invoice to trigger file deletion.

The Welcart e-Commerce WordPress plugin before 2.12.1 does not regenerate the session identifier on authentication and sets the session identifier from a user-supplied request parameter, allowing an unauthenticated attacker to fixate a shop member's session and take over their customer account after the victim logs in through an attacker-crafted request.

Unauthenticated Cross Site Scripting (XSS) in Welcart e-Commerce versions up to 2.11.31. An attacker can inject malicious script without authentication.

The Welcart e-Commerce WordPress plugin before 2.11.33 does not verify the authenticity of its convenience-store / bank-transfer settlement callback: an unauthenticated request can flip an order from unpaid to settled purely from an order number and a status flag, with no signature, amount, or origin check. Because these are pay-later methods, an attacker can mark their own unpaid order as settled and obtain fulfilment without paying.

The Welcart e-Commerce WordPress plugin before 2.11.34 does not sanitise or escape a product field before outputting it on the product pages, allowing users with the Author role and above to inject arbitrary web scripts that execute in the browser of any visitor viewing the product page.

Welcart e-Commerce versions up to 2.11.28 have an issue with unauthenticated access that can lead to broken access control.