CVE-2026-25467

User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder <= 5.3.0 - Unauthenticated Arbitrary Shortcode Execution

2026-10-29 00:00
Filip Kowalski

Strategic Overview

Status
Patched in 5.3.1
Affected Plugin
User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder
Affected Version
<= 5.3.0
CVSS
6.5Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation
CVE
CVE-2026-25467
View all User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder vulnerabilities

At a glance

CVE-2026-25467 is a medium-severity Improper Neutralization of Input During Web Page Generation vulnerability in the User Registration & Membership WordPress plugin, affecting versions <= 5.3.0. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.3.1; sites on affected versions should update now. Disclosed October 2026, reported by Filip Kowalski.

Vulnerability Overview

The The User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 5.3.0. This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.

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-79: Improper Neutralization of Input During Web Page Generation

Reaching this weakness in User Registration & Membership <= 5.3.0 takes no account at all. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For User Registration & Membership the fix is 5.3.1: builds <= 5.3.0 are affected, anything from 5.3.1 onward is not.

Remediation

Update to version 5.3.1, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: User Registration & Membership 5.3.1 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-25467https://www.wordfence.com/threat-intel/vulnerabilities/id/536b924b-44ec-4346-9578-74a7e3836f1bhttps://nvd.nist.gov/vuln/detail/CVE-2026-25467

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