# Payment forms, Buy now buttons, and Invoicing System | GetPaid <= 2.8.54 - Unauthenticated Insecure Direct Object Reference to Invoice Modification via 'invoice_id' Parameter

- **ID:** WPSEC-2026-1614
- **Plugin:** Payment forms, Buy now buttons, and Invoicing System | GetPaid (`invoicing`), https://wordpress.org/plugins/invoicing/
- **Affected versions:** all versions before 2.8.55
- **Fixed in:** 2.8.55 (Update to 2.8.55 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-639
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-25)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/invoicing
- **Fix released:** 2026-07-08
- **Published:** 2026-10-24
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1614/

## Description

The Payment forms, Buy now buttons, and Invoicing System | GetPaid plugin for WordPress is vulnerable to Insecure Direct Object Reference via the 'invoice_id' payment form parameter in all versions up to, and including, 2.8.54, due to a missing check on whether the submitter owns the referenced invoice or supplied its key. This makes it possible for unauthenticated attackers to submit a payment form checkout against any other user's unpaid invoice, overwriting its billing email, items, fees, discounts, address and payment gateway.

## References

- https://wpsec.com/vuln/WPSEC-2026-1614/
- https://plugins.svn.wordpress.org/invoicing/tags/2.8.55/
- https://wordpress.org/plugins/invoicing/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1614/

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.