PayPay for WooCommerce accepts unauthenticated forged payment notices
Payment Gateway PayPay for WooCommerce versions 0.5 through 0.9.3 act on payment notifications without verifying their authenticity. An unauthenticated attacker who knows the store's merchant identifier can mark arbitrary orders paid or change them to cancelled or failed. The authoritative export does not identify the callback route, notification fields, or signature-validation function.
- Component
- Payment Gateway PayPay for WooCommerce
- Plugin slug
payment-gateway-paypay-for-woocommerce- Affected
- 0.5 through 0.9.3
- Safe version
- See mitigation notes
- Published
- Sep 11, 2026
This CVE was published Sep 11, 2026 and is one of 1 known issue for this plugin.
Update, patch or deactivate.
No fixed release is confirmed in the authoritative export. Deactivate the gateway or obtain a vendor-confirmed remediation that cryptographically authenticates each notification and binds its merchant, transaction, amount, currency, and order identifiers before changing order state. Audit affected order transitions and reconcile them against the payment provider.
No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The Payment Gateway PayPay for WooCommerce WordPress plugin from 0.5 to 0.9.3 does not verify the authenticity of the payment notifications it receives before acting on them, allowing unauthenticated attackers who know the store's merchant identifier to mark arbitrary orders as paid, or to cancel or fail them.
CVE / CNA vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N