What is CVE-2026-11964?

CVE-2026-11964 is a critical-severity vulnerability in User Registration & Membership, classified under CWE-287 IMPROPER AUTHENTICATION. CVSS score: 9.1/10. Published 2026-07-13.

How severe is CVE-2026-11964?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in User Registration & Membership

CVE-2026-11964

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.

Published 2026-07-13 · last modified 2026-07-13.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.005 (37.6th percentile), scored 2026-10-12.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

User Registration & Membership — versions 0

References

wpscan.com/vulnerability/faf55649-8f76-4abf-a6b9-0d0774e22d29/ (technical-description, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-11964?: CVE-2026-11964 is a critical-severity vulnerability in User Registration & Membership, classified under CWE-287 IMPROPER AUTHENTICATION. CVSS score: 9.1/10. Published 2026-07-13.
How severe is CVE-2026-11964?: Critical severity. CVSS v3 base score is 9.1 out of 10.