User Registration & Membership <= 5.2.1 - Authenticated (Subscriber+) Insecure Direct Object Reference to Membership Tier Modification
Strategic Overview
- Status
- Patched in 5.2.2
- Affected Version
<= 5.2.1- CVSS
- 4.3Medium
- Weakness type
- CWE-639 · Authorization Bypass Through User-Controlled Key
- CVE
CVE-2026-11963
At a glance
CVE-2026-11963 is a medium-severity Authorization Bypass Through User-Controlled Key vulnerability in the User Registration & Membership WordPress plugin, affecting versions <= 5.2.1. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 5.2.2; sites on affected versions should update now. Disclosed June 2026, reported by Revanth Hari Narayana Matte.
Vulnerability Overview
The User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.2.1 due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Subscriber-level access and above, to register as other membership tiers.
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 interaction from a victim user.
CWE-639: Authorization Bypass Through User-Controlled Key
Reaching this weakness in User Registration & Membership <= 5.2.1 takes an account at Subscriber level or above. Authorization bypass through a user-controlled key, often called insecure direct object reference, means the application looks up a record by an identifier from the request without checking that the caller owns it.
Changing a number in the request is enough to read or modify other users' records, which on commerce and membership sites means customer data. For User Registration & Membership the fix is 5.2.2: builds <= 5.2.1 are affected, anything from 5.2.2 onward is not.
Remediation
Update to version 5.2.2, or a newer patched version
How does WordSec protect against this?
Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: User Registration & Membership 5.2.2 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder
- 9.9CVE-2023-3342: User Registration <= 3.0.2 Arbitrary File Upload
CVE-2023-3342 - 9.8CVE-2026-32488: User Registration & Membership RCE
CVE-2026-32488 - 9.8CVE-2026-1492: User Registration & Membership Privilege Escalation
CVE-2026-1492 - 9.8CVE-2025-2563: User Registration & Membership Privilege Escalation
CVE-2025-2563 - 8.8CVE-2024-2417: User Registration Authenticated (Subscriber+)
CVE-2024-2417 - 8.8CVE-2023-3343: User Registration <= 3.0.1 PHP Object Injection
CVE-2023-3343 - 8.8CVE-2022-3912: User Registration <= 2.2.4 Arbitrary File Upload
CVE-2022-3912 - 8.1CVE-2026-11961: User Registration & Membership Privilege Escalation
CVE-2026-11961
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