5.4
MEDIUM CVSS 3.1
CVE-2026-4056
User Registration & Membership <= 5.1.4 - Missing Authorization to Authenticated (Contributor+) Content Access Rule Manipulation
Description

The User Registration & Membership plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the Content Access Rules REST API endpoints in versions 5.0.1 through 5.1.4. This is due to the `check_permissions()` method only checking for `edit_posts` capability instead of an administrator-level capability. This makes it possible for authenticated attackers, with Contributor-level access and above, to list, create, modify, toggle, duplicate, and delete site-wide content restriction rules, potentially exposing restricted content or denying legitimate user access.

INFO

Published Date :

March 24, 2026, 12:16 a.m.

Last Modified :

March 24, 2026, 12:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-4056 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update the User Registration & Membership plugin to fix missing capability checks in REST API endpoints.
  • Update the User Registration & Membership plugin.
  • Verify administrator-level capability checks are implemented.
  • Restrict access to REST API endpoints.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-4056 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-4056 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-4056 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-4056 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 24, 2026

    Action Type Old Value New Value
    Added Description The User Registration & Membership plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the Content Access Rules REST API endpoints in versions 5.0.1 through 5.1.4. This is due to the `check_permissions()` method only checking for `edit_posts` capability instead of an administrator-level capability. This makes it possible for authenticated attackers, with Contributor-level access and above, to list, create, modify, toggle, duplicate, and delete site-wide content restriction rules, potentially exposing restricted content or denying legitimate user access.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
    Added CWE CWE-862
    Added Reference https://plugins.trac.wordpress.org/browser/user-registration/tags/5.1.1/modules/content-restriction/includes/RestApi/controllers/version1/class-urcr-content-access-rules.php#L116
    Added Reference https://plugins.trac.wordpress.org/browser/user-registration/trunk/modules/content-restriction/includes/RestApi/controllers/version1/class-urcr-content-access-rules.php#L116
    Added Reference https://plugins.trac.wordpress.org/changeset/3485702/user-registration/trunk/modules/content-restriction/includes/RestApi/controllers/version1/class-urcr-content-access-rules.php
    Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/7bb5a5a2-9644-4850-a5f9-7c925af000c8?source=cve
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.