CVE-2026-43928

FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, the PayPalEmail payment adapter accepts PayPal IPN callbacks and credits the IPN-supplied amount mcgross to the client's balance without validating it against the invoice total. Combined with a $0.05...

EUVD-2026-39949

The RegistrationMagic – Custom Registration Forms, User Registration, Payment, and User Login plugin for WordPress is vulnerable to Authentication Bypass via Insufficient Verification of Data Authenticity in all versions up to and including 6.0.8.6. This is due to the PayPal IPN callback handler...

GHSA-MMW7-WQ3C-WF9P WWBN AVideo Affected by a PayPal IPN Replay Attack Enabling Wallet Balance Inflation via Missing Transaction Deduplication in ipn.php

Summary The PayPal IPN v1 handler at plugin/PayPalYPT/ipn.php lacks transaction deduplication, allowing an attacker to replay a single legitimate IPN notification to repeatedly inflate their wallet balance and renew subscriptions. The newer ipnV2.php and webhook.php handlers correctly deduplicate...

CVE-2026-39366

WWBN AVideo is an open source video platform. In versions 26.0 and prior, the PayPal IPN v1 handler at plugin/PayPalYPT/ipn.php lacks transaction deduplication, allowing an attacker to replay a single legitimate IPN notification to repeatedly inflate their wallet balance and renew subscriptions...

CVE-2009-1366

Cross-site scripting XSS vulnerability in Website\admin\Sales\paypalipn.aspx in DotNetNuke DNN before 4.9.3 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors related to "name/value pairs" and "paypal IPN functionality."...