CVE-2026-39366: WWBN AVideo Affected by a PayPal IPN Replay Attack Enabling Wallet Balance Inflation via Missing Transaction Deduplication in ipn.php

April 8, 2026

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 via PayPalYPT_log entries, but the v1 handler was never updated and remains actively referenced as the notify_url for billing plans.

References

github.com/WWBN/AVideo
github.com/WWBN/AVideo/commit/8f53e9d9c6aaa07d51ace30691981edbbfb5ca1c
github.com/WWBN/AVideo/security/advisories/GHSA-mmw7-wq3c-wf9p
github.com/advisories/GHSA-mmw7-wq3c-wf9p
nvd.nist.gov/vuln/detail/CVE-2026-39366

Code Behaviors & Features

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