# Payment forms, Buy now buttons, and Invoicing System | GetPaid <= 2.8.62 - Unauthenticated Price Manipulation via Payment Form Item Quantity

- **ID:** WPSEC-2026-1612
- **Plugin:** Payment forms, Buy now buttons, and Invoicing System | GetPaid (`invoicing`), https://wordpress.org/plugins/invoicing/
- **Affected versions:** from 2.0.0 before 2.8.63
- **Fixed in:** 2.8.63 (Update to 2.8.63 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-20
- **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:** 2026-10-23
- **Published:** 2026-10-24
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1612/

## Description

The Payment forms, Buy now buttons, and Invoicing System | GetPaid plugin for WordPress is vulnerable to price manipulation in versions 2.0.0 to, and including, 2.8.62, due to insufficient validation of item quantities in payment form submissions and buy-now item lists, which accepted negative values. This makes it possible for unauthenticated attackers to lower the total of a checkout and pay less for other items in the same order.

## References

- https://wpsec.com/vuln/WPSEC-2026-1612/
- https://plugins.svn.wordpress.org/invoicing/tags/2.8.63/
- https://wordpress.org/plugins/invoicing/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1612/

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.