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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS

• CVE-2026-39366: 0.17% estimated exploitation activity in the next 30 days; percentile 6.34 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 via PayPalYPTlog entries, but the v1 handler was never updated and remains actively referenced as the notifyurl for billing plans. Details When a recurring payment IPN arrives at ipn.php, the handler: 1. Verifies authenticity via PayPalYPT::IPNcheck() (line 16), which sends the POST data to PayPal's cmd=notify-validate endpoint. PayPal confirms the data is genuine but this verification is stateless — PayPal returns VERIFIED for the same authentic data on every submission. 2. Looks up the subscription from recurringpaymentid and directly credits the user's wallet (lines 41-53): No txnid uniqueness check. No PayPalYPTlog entry created. No deduplication of any kind. Compare with the patched…

Published by the source

8 Apr 2026, 00:08 UTC

Last modified by the source

8 Apr 2026, 00:08 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-mmw7-wq3c-wf9p

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# Patch Next advisory brief: CVE-2026-39366

Advisory: WWBN AVideo Affected by a PayPal IPN Replay Attack Enabling Wallet Balance Inflation via Missing Transaction Deduplication in ipn.php
IDs: CVE-2026-39366, GHSA-mmw7-wq3c-wf9p
Record: https://patchnext.com/advisories/cve-2026-39366 (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist wwbn/avideo: affected <= 26.0

## Suggested inspection (read-only)
- Packagist wwbn/avideo: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on wwbn/avideo.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-mmw7-wq3c-wf9p (GitHub-reviewed advisory GHSA-mmw7-wq3c-wf9p lists affected ranges: Packagist wwbn/avideo >=0 <=26.0)

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