# Accept PayPal Payments using Contact Form 7 <= 4.0.6 - Unauthenticated Missing Authorization to Arbitrary PayPal Refund

- **ID:** WPSEC-2026-0643
- **Plugin:** Accept PayPal Payments using Contact Form 7 (`contact-form-7-paypal-extension`), https://wordpress.org/plugins/contact-form-7-paypal-extension/
- **Affected versions:** from 4.0.0 before 4.0.7
- **Fixed in:** 4.0.7 (Update to 4.0.7 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 2026-10-08)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/contact-form-7-paypal-extension
- **Fix released:** 2026-10-07
- **Published:** 2026-10-08
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0643/

## Description

The Accept PayPal Payments using Contact Form 7 plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the refund AJAX action, which was also registered for unauthenticated users and performed no nonce check or validation that the supplied entry, form and transaction belonged together, in versions 4.0.0 up to, and including, 4.0.6. This makes it possible for unauthenticated attackers to trigger PayPal refunds of transactions using the site's stored PayPal API credentials and mark payment entries as refunded.

## References

- https://wpsec.com/vuln/WPSEC-2026-0643/
- https://plugins.svn.wordpress.org/contact-form-7-paypal-extension/tags/4.0.7/
- https://wordpress.org/plugins/contact-form-7-paypal-extension/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0643/

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.