Auth bypass in User Registration & Membership

CVE-2026-11966

The User Registration & Membership WordPress plugin before 5.2.3 does not perform a capability check for unauthenticated callers on one of its membership payment actions and acts on a caller-supplied user identifier, allowing unauthenticated attackers to delete recently-registered, payment-pending user accounts.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 22.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-11966: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

  • User Registration & Membership — versions 4.2.3

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-11966?
CVE-2026-11966 is a medium-severity vulnerability in User Registration & Membership, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.3/10. Published 2026-07-17.
How severe is CVE-2026-11966?
Medium severity. CVSS v3 base score is 5.3 out of 10.