CVE-2026-78064

Joomla Extension - j2commerce.com - Guest checkout address disclosure to any authenticated user (IDOR) in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6 - `editAddress()` redirected non-owners away only when the loaded address row had a **non-empty** `user_id` belonging to someone else. Guest-checkout address rows have an empty `user_id`, so that check never triggered for them — any logged-in account guessing a small, sequential `address_id` got a guest customer's full name, street address, and phone number rendered prefilled into the edit form.

Joomla Extension - j2commerce.com - Reflected XSS via `filter_tag`, `pricefrom` and `priceto` in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6 - Four task handlers accepted a base64-encoded URL from user input and redirected to it without validating the destination host, enabling phishing using the shop's trusted domain. No authentication required.

Joomla Extension - j2commerce.com - Unauthenticated PayPal callback forgery leading to order confirmation fraud in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6 - The PayPal IPN listener's signature check (`_validateIPN()`) accepted `UNVERIFIED` and any non-`INVALID` response as valid, made its verification request with `CURLOPT_SSL_VERIFYPEER` disabled, and stored its verdict in a field nothing downstream ever checked — so processing continued regardless of the outcome. Separately, the paid-amount comparison only ran when `mc_gross` was a positive number; omitting the field from the POST body (`floatval(null) == 0`) skipped the check entirely. Combined with a merchant-configured `receiver_email` and a sequential, enumerable order id read from the `custom` field, an anonymous POST was enough to move a pending order straight to `CONFIRMED` with no payment, or force another customer's pending order to `FAILED`. `paypalv2.php` performed no amount check under any circumstances.

Joomla Extension - j2commerce.com - Missing authorization on Apps controller delegation chain in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6 - J2StoreControllerApps's appTask delegation path instantiates app-plugin controllers with no ACL check anywhere in the code. Additionally, applocalizationdata::getInstallerTool() used a caller-influenced table name with no allow-list, enabling path-traversal-capable file read/execute.

Joomla extension J2Store (versions 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5) is vulnerable to Stored Cross-Site Scripting (XSS) through the guest checkout billing address fields. An unauthenticated attacker exploits a filter bypass in Joomla's Input::getArray() combined with PHP's variables_order=EGPCS (Cookie overrides POST in $_REQUEST) to store unsanitized HTML in fields such as billing_first_name.

Joomla Extension - j2commerce.com - Open redirect in cart controller in J2Store 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5 - Four task handlers accepted a base64-encoded URL from user input and redirected to it without validating the destination host, enabling phishing using the shop's trusted domain. No authentication required.

Joomla Extension - j2commerce.com - Unauthenticated file upload with missing directory protection in J2Store 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5 - The file upload endpoint accepted POST requests from unauthenticated visitors with no CSRF token. Compounding this, the installer manifest omitted the upload and invoices directories, causing fresh installs to deploy those directories without .htaccess/web.config protection, making uploaded files directly web-accessible.

Joomla Extension - j2commerce.com - Cross-customer order replication in J2Store 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5 - An authenticated user could supply another customer's order_id to copy their cart contents and address data into the attacker's session. The CSRF token was validated but ownership was not checked.

Joomla extension J2Store (versions 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5) allows an unauthenticated visitor to supply any order_id as a query parameter to render the full checkout confirmation page for that order, including line items, prices, and totals.

Joomla Extension - j2commerce.com - Download quota manipulation in J2Store 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5 - An authenticated user with a valid order token could increment the download limit counter on a download record belonging to a different order. The endpoint also lacked a CSRF token.