CVE-2026-3601

User Registration & Membership <= 5.1.4 - Missing Authorization to Authenticated (Contributor+) Limited Page Content Modification

2026-05-04 19:57
Hunter Jensen (skid)

Strategic Overview

Status
Patched in 5.1.5
Affected Plugin
User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder
Affected Version
<= 5.1.4
CVSS
4.3Medium
Weakness type
CWE-862 · Missing Authorization
CVE
CVE-2026-3601
View all User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder vulnerabilities

At a glance

CVE-2026-3601 is a medium-severity Missing Authorization vulnerability in the User Registration & Membership WordPress plugin, affecting versions <= 5.1.4. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 5.1.5; sites on affected versions should update now. Disclosed May 2026, reported by Hunter Jensen (skid).

Vulnerability Overview

The User Registration & Membership plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `embed_form_action()` function in all versions up to, and including, 5.1.4. This makes it possible for authenticated attackers, with Contributor-level access and above, to append shortcode content to arbitrary pages they do not own or have permission to edit.

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-862: Missing Authorization

User Registration & Membership <= 5.1.4 carries this weakness at embed_form_action(), and reaching it takes an account at Contributor level or above. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For User Registration & Membership the fix is 5.1.5: builds <= 5.1.4 are affected, anything from 5.1.5 onward is not.

Remediation

Update to version 5.1.5, 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 5.1.5 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-3601https://www.wordfence.com/threat-intel/vulnerabilities/id/c8798fb2-4cab-4960-9e32-fd74bb4a5091https://nvd.nist.gov/vuln/detail/CVE-2026-3601

Related records

Other vulnerabilities in User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C