CVE-2026-11964
User Registration & Membership < 5.2.2 - Unauthenticated PayPal Webhook Signature Verification Bypass Leading to Membership Activation
CVSS Score
9.1
EPSS Score
0.0%
EPSS Percentile
0th
The User Registration & Membership WordPress plugin before 5.2.2 does not verify the authenticity of incoming payment-provider webhook notifications before acting on them, allowing unauthenticated attackers to forge a payment-approved event and activate a paid membership subscription without completing a real payment.
| Vendor | unknown |
| Product | user registration & membership |
| Published | Jul 13, 2026 |
| Last Updated | Jul 13, 2026 |
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Affected Versions
Unknown / User Registration & Membership
0 < 5.2.2
References
Credits
Alessandro Greco aka Aleff Giovanbattista Ianni (University of Calabria - UNICAL) WPScan