# ЮKassa для WooCommerce <= 2.17.3 - Unauthenticated Saved Payment Method Injection via Forged Payment Notification

- **ID:** WPSEC-2026-2509
- **Plugin:** ЮKassa для WooCommerce (`yookassa`), https://wordpress.org/plugins/yookassa/
- **Affected versions:** all versions before 2.17.4
- **Fixed in:** 2.17.4 (Update to 2.17.4 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-345
- **Usage among sites WPSec scans:** plugin Low, affected versions None seen (as of 2026-11-04)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/yookassa
- **Fix released:** 2026-11-03
- **Published:** 2026-11-04
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2509/

## Description

The ЮKassa для WooCommerce plugin for WordPress is vulnerable to Insufficient Verification of Data Authenticity via the '?yookassa=callback' payment notification endpoint in all versions up to, and including, 2.17.3, due to the plugin trusting the payment object in the unverified notification body (metadata such as wp_user_id, the payment method and the payment status) and acting on it before it re-fetches the payment from the YooKassa API. This makes it possible for unauthenticated attackers to send forged notifications that save attacker-defined payment method tokens to arbitrary customer accounts.

## References

- https://wpsec.com/vuln/WPSEC-2026-2509/
- https://plugins.svn.wordpress.org/yookassa/tags/2.17.4/
- https://wordpress.org/plugins/yookassa/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2509/

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.