---
id: CVE-2026-73316
title: >-
  XenForo before 2.3.13 contains a payment replay vulnerability in the PayPal
  REST payment provider that allows attackers to process the same webhook
  payload multiple times by exploiting a missing duplicate transaction ID check
summary: >-
  XenForo before 2.3.13 contains a payment replay vulnerability in the PayPal
  REST payment provider that allows attackers to process the same webhook
  payload multiple times by exploiting a missing duplicate transaction ID check.
  Attackers …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-345
vendor: xenforo
product: xenforo
affected:
  - xenforo < 2.3.13
patched:
  - xenforo 2.3.13
published: '2026-09-08'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T20:31:36.417'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73316'
references:
  - url: 'https://bombobombone.github.io/posts/cve-2026-73316/'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/BomboBombone/CVE-2026-73316'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/xenforo-payment-replay-via-paypal-rest-payment-provider
    label: disclosure@vulncheck.com
  - url: >-
      https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/
    label: disclosure@vulncheck.com
  - url: >-
      https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/
    label: disclosure@vulncheck.com
tags:
  - nvd
  - exploit-available
  - cve.org
epss: 0.00265
epssPercentile: 0.16406
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/BomboBombone/CVE-2026-73316'
  checkedAt: '2026-09-26T09:05:58.809Z'
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-10T13:50:23.706210Z'
ingestedAt: '2026-09-08T15:33:26.984Z'
---

## Overview

XenForo before 2.3.13 contains a payment replay vulnerability in the PayPal REST payment provider that allows attackers to process the same webhook payload multiple times by exploiting a missing duplicate transaction ID check. Attackers can replay a valid webhook payload to trigger duplicate payment events, resulting in repeated subscription activations and unauthorized account upgrades.

## Affected

- `xenforo < 2.3.13`

## Remediation

Upgrade past the affected range:

- `xenforo 2.3.13`