WP Overnight vulnerabilities and threats

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress versions up to 5.16.5 has a vulnerability that allows unauthenticated attackers to access complete invoice PDFs of other customers. This occurs via the 'invoice_number' parameter in the document filename when the plugin's yearly invoice number reset option is enabled. Exploitation requires the attacker to place a guest-checkout order triggering a processing email within 60 seconds of a victim's order sharing the same yearly-reset invoice number. The exposed invoice contains sensitive information including billing identity, shipping address, private order notes, line items, prices, dates, order ID, and invoice number.

The PDF Invoices & Packing Slips for WooCommerce WordPress plugin is affected by a stored Cross-Site Scripting (XSS) vulnerability in versions up to and including 5.16.4. The flaw arises from insufficient input sanitization and output escaping in parameters such as billing_address.first_name, last_name, company, and customer_note. An incomplete fix introduced in version 5.16.2 fails to block entity-encoded payloads, allowing attackers to inject arbitrary scripts that execute when a user views the affected page.

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Billing First Name / Last Name / Company Fields in all versions up to, and including, 5.16.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload survives initial storage because WooCommerce's sanitize_text_field() and wc_clean() do not strip entity-encoded strings containing no literal '<' character, allowing unauthenticated guest-checkout orders to plant the malicious content.

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.14.0 via the generate_document_shortcode due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with contributor-level access and above, to mint publicly accessible, session-free download links for arbitrary third-party orders, exposing customer names, billing and shipping addresses, email addresses, phone numbers, order and invoice numbers, line items, totals, payment details, and customer notes contained in those orders' invoices and packing slips. Exploitation requires the plugin's Document link access type setting to be configured to 'full'; with the default 'logged_in' value, generated URLs are signed with a per-session nonce rather than the order_key, making the shortcode path unexploitable for unauthorized access to third-party orders.

A high-severity vulnerability (CVE-2026-39472) exists in WP Overnight's WooCommerce PDF Invoices & Packing Slips plugin before version 5.9.0. It involves PHP Object Injection due to deserialization of untrusted data by users with shop manager privileges. This can lead to complete compromise of confidentiality, integrity, and availability of the affected system. No official patch or remediation guidance is currently provided.

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.6.0 via the `wpo_ips_edi_save_order_customer_peppol_identifiers` AJAX action due to missing capability checks and order ownership validation. This makes it possible for authenticated attackers, with Subscriber-level access and above, to modify Peppol/EDI endpoint identifiers (`peppol_endpoint_id`, `peppol_endpoint_eas`) for any customer by specifying an arbitrary `order_id` parameter on systems using Peppol invoicing. This can affect order routing on the Peppol network and may result in payment disruptions and data leakage.

Missing Authorization vulnerability in WP Overnight WooCommerce PDF Invoices & Packing Slips woocommerce-pdf-invoices-packing-slips allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects WooCommerce PDF Invoices & Packing Slips: from n/a through <= 4.9.1.

Missing Authorization vulnerability in WP Overnight WooCommerce PDF Invoices & Packing Slips woocommerce-pdf-invoices-packing-slips allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects WooCommerce PDF Invoices & Packing Slips: from n/a through <= 3.8.6.

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via several parameters in versions up to, and including, 3.8.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Server-Side Request Forgery in versions up to, and including, 3.8.0 via the transform() function. This can allow unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in WP Overnight PDF Invoices & Packing Slips for WooCommerce.This issue affects PDF Invoices & Packing Slips for WooCommerce: from n/a through 3.7.5.