CVE-2026-11965

User Registration & Membership <= 5.1.0 - Unauthenticated Payment Bypass

2026-06-11 00:00
John Umoru

At a glance

CVE-2026-11965 is a medium-severity Client-Side Enforcement of Server-Side Security vulnerability in the User Registration & Membership WordPress plugin, affecting versions <= 5.1.0. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.2.0; sites on affected versions should update now. Disclosed June 2026, reported by John Umoru.

Vulnerability Overview

The User Registration & Membership plugin for WordPress is vulnerable to Payment Bypass in versions up to, and including, 5.1.0. This is due to a lack of server-side payment verification. This makes it possible for unauthenticated attackers to bypass payments.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-602: Client-Side Enforcement of Server-Side Security

The product is composed of a server that relies on the client to implement a mechanism that is intended to protect the server.

Remediation

Update to version 5.2.0, or a newer patched version

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: User Registration & Membership 5.2.0 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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