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CVE-2026-73316

XenForo < 2.3.13 Payment Replay via PayPal REST Payment Provider

Published: Sep 8, 2026Updated: Sep 11, 2026 Sources: CVE List NVDCWE-345
7.5HIGH
NVD MITRE
EPSS Score
0.2%
Top 90.0%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:HIntegrity
High
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-345

Affected Products

XenForo
commercialaka xenforo forum
XenForoOn-prem
Web & CMS Plugins / forum-wiki
and 1 more affected products View all →

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://bombobombone.github.io/posts/cve-2026-73316/
bombobombone.github.io
https://github.com/BomboBombone/CVE-2026-73316
github.com
https://www.vulncheck.com/advisories/xenforo-payment-replay-via-paypal-rest-payment-provider
vulncheck.com
and 2 more references View all →

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