# Woo Billingo Plus <= 5.4 - Missing Authorization to Invoice Preview Generation

- **ID:** WPSEC-2026-2520
- **Plugin:** Woo Billingo Plus (`woo-billingo-plus`), https://wordpress.org/plugins/woo-billingo-plus/
- **Affected versions:** all versions before 5.4.1
- **Fixed in:** 5.4.1 (Update to 5.4.1 or later.)
- **Severity:** Medium 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-862
- **Usage among sites WPSec scans:** plugin Low, affected versions None seen (as of 2026-11-04)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/woo-billingo-plus
- **Fix released:** 2026-11-03
- **Published:** 2026-11-04
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2520/

## Description

The Enhanced Integration for Billingo and WooCommerce (woo-billingo-plus) plugin for WordPress is vulnerable to unauthorized access in all versions up to, and including, 5.4 due to a missing capability check in the invoice preview handler (WC_Billingo_Plus_Invoice_Preview::load_preview_template), which ran the invoice data generation for any order ID supplied in the wc_billingo_plus_preview query parameter before the only permission check, which lived in the preview template that was included afterwards. This makes it possible for unauthenticated attackers to trigger the invoice generation code path for arbitrary orders, including the Billingo API partner-creation requests it performs.

## References

- https://wpsec.com/vuln/WPSEC-2026-2520/
- https://plugins.svn.wordpress.org/woo-billingo-plus/tags/5.4.1/
- https://wordpress.org/plugins/woo-billingo-plus/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2520/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.