CVE-2026-11964

User Registration & Membership < 5.2.2 - Unauthenticated PayPal Webhook Signature Verification Bypass Leading to Membership Activation

Critical · published July 13, 2026

CVSS v3.1
9.1
EPSS
0%
Percentile
38.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00454 · 38.4th percentile
Published
2026-07-13T06:00Z
EPSS history
Timeline
  • 13 JUL 06:00Z
    User Registration & Membership < 5.2.2 - Unauthenticated PayPal Webhook Signature Verification Bypass Leading to Membership Activation
    cvelistv5