Vulnerability details
CVE-2026-11964
User Registration & Membership
User Registration & Membership < 5.2.2 - Unauthenticated PayPal Webhook Signature Verification Bypass Leading to Membership Activation
CVSS 3.1
9.1Critical
Official 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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.1Critical | 3.1 | CISA ADP / Vulnrichment (CISA-ADP) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| — | User Registration & Membership | v < 5.2.2 | CVEProject cvelistV5 (CNA) |
References and advisories
1- https://wpscan.com/vulnerability/faf55649-8f76-4abf-a6b9-0d0774e22d29/ exploitvdb-entrytechnical-description
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Details
- Published
- 2026-07-13
- Last updated
- 2026-07-13
- State
- Published
- Assigner (CNA)
- WPScan
Exploit prediction (EPSS)
0.45%
Probability of exploitation in 30 days
39.5%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- Proof of concept
- Technical impact
- Total
Weaknesses (CWE)
- —