User Registration & Membership <= 5.1.2 - Insecure Direct Object Reference to Unauthenticated Limited User Deletion
Strategic Overview
- Status
- Patched in 5.1.3
- Affected Version
<= 5.1.2- CVSS
- 5.3Medium
- Weakness type
- CWE-284 · Improper Access Control
- CVE
CVE-2026-2356
At a glance
CVE-2026-2356 is a medium-severity Improper Access Control vulnerability in the User Registration & Membership WordPress plugin, affecting versions <= 5.1.2. 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 5.1.3; sites on affected versions should update now. Disclosed February 2026, reported by h0xilo.
Vulnerability Overview
The User Registration & Membership – Custom Registration Form, Login Form, and User Profile plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.2 via the 'register_member' function, due to missing validation on the 'member_id' user controlled key. This makes it possible for unauthenticated attackers to delete arbitrary user accounts that newly registered on the site who has the 'urm_user_just_created' user meta set.
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-284: Improper Access Control
User Registration & Membership <= 5.1.2 carries this weakness at register_member, and reaching it takes no account at all. Improper access control means the code decides what a caller may do using something other than their actual permissions, so the decision can be wrong without any check appearing to be missing.
Whoever can shape the request decides the answer, so the protected action runs for callers the code never meant to allow. For User Registration & Membership the fix is 5.1.3: builds <= 5.1.2 are affected, anything from 5.1.3 onward is not.
Remediation
Update to version 5.1.3, 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 5.1.3 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
Related records
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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