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

> Attackers can replay PayPal IPN notifications to inflate wallet balances and renew subscriptions due to missing transaction deduplication in the v1 handler.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-mmw7-wq3c-wf9p

## What is CVE-2026-39366?

CVE-2026-39366 is a medium-severity vulnerability in Wwbn Avideo, published on 7 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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. 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.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity)

## Which versions are affected by CVE-2026-39366?

2 open source packages ship an affected version, including wwbn/avideo. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `wwbn/avideo` | Packagist | All versions to 26.0 | None |
| `wwbn/avideo` | Packagist | All versions to 26.0 | None |

Products: Wwbn Avideo.

## How do I fix CVE-2026-39366?

No fix has been published for CVE-2026-39366 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-39366 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39366 exists.

## Other vulnerabilities in Wwbn Avideo

- [CVE-2026-40911](https://insights.sbomify.com/CVE-2026-40911/): WWBN AVideo YPTSocket WebSocket Broadcast Relay Leads to Unauthenticated Cross-User JavaScript Execution via Client-Side eval() Sinks (critical 10.0)
- [CVE-2026-33478](https://insights.sbomify.com/CVE-2026-33478/): AVideo Multi-Chain Attack: Unauthenticated Remote Code Execution via Clone Key Disclosure, Database Dump, and Command Injection (critical 10.0)
- [CVE-2022-30534](https://insights.sbomify.com/CVE-2022-30534/): Command injection in AVideo (critical 9.9)
- [CVE-2022-30547](https://insights.sbomify.com/CVE-2022-30547/): Path traversal in AVideo (critical 9.9)
- [CVE-2022-32572](https://insights.sbomify.com/CVE-2022-32572/): Command injection in AVideo (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39366 and fix it if it is affected.

What it is: CVE-2026-39366 is a medium-severity vulnerability in Wwbn Avideo, published on 7 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39366 exists.

Affected packages and fixed versions:
- wwbn/avideo (Packagist): affected all versions up to 26.0; no fix listed
- wwbn/avideo (Packagist): affected all versions up to 26.0; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-39366/ (Markdown: https://insights.sbomify.com/CVE-2026-39366/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39366
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39366
- OSV: https://osv.dev/vulnerability/CVE-2026-39366

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-39366/
Summaries are generated and may contain mistakes; the official description above is the record.