CVE-2026-11964

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

Published Jul 13, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Weaknesses CWE-287
Type Values Removed Values Added
Weaknesses CWE-284
CWE-345
Type Values Removed Values Added
Weaknesses CWE-284
CWE-345
Type Values Removed Values Added
Weaknesses CWE-284
CWE-307
Type Values Removed Values Added
Weaknesses CWE-284
CWE-307
Type Values Removed Values Added
Weaknesses CWE-640
Type Values Removed Values Added
Weaknesses CWE-640
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title User Registration & Membership < 5.2.2 - Unauthenticated PayPal Webhook Signature Verification Bypass Leading to Membership Activation
References

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
WPScan
Published
Updated
Jul 13, 2026, 3:52 PM
Reserved
Jun 11, 2026, 8:46 AM
Status
Deferred
Published
Jul 13, 2026, 7:16 AM
Modified
Jul 13, 2026, 6:05 PM