CVE-2026-73316
XenForo < 2.3.13 Payment Replay via PayPal REST Payment Provider
- State
- Published
- Severity
- 8.7 High
- Published
- Sep 8, 2026
- Updated
- Oct 1, 2026
- Reserved
- Aug 11, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | VulnCheck |
Weaknesses
- CWE-345 Insufficient Verification of Data Authenticity
Affected Products
| Product | Versions |
|---|---|
XenForoXenForo |
|
References
- Vendor Advisoryvendor-advisorypatch
- Release Notesrelease-notes
- Researcher Advisorytechnical-description
- Researcher PoCexploit
- https://www.vulncheck.com/advisories/xenforo-payment-replay-via-paypal-rest-payment-providerthird-party-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.