CVE-2026-4248

Ultimate Member <= 2.11.2 - Authenticated (Contributor+) Sensitive Information Exposure to Account Takeover via Shortcode Template Tag

2026-03-27 09:48
HDH

At a glance

CVE-2026-4248 is a high-severity Improper Authorization vulnerability in the Ultimate Member WordPress plugin, affecting versions <= 2.11.2. It carries a CVSS score of 8.0 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 2.11.3; sites on affected versions should update now. Disclosed March 2026, reported by HDH.

Vulnerability Overview

The Ultimate Member plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.11.2. This is due to the '{usermeta:password_reset_link}' template tag being processed within post content via the '[um_loggedin]' shortcode, which generates a valid password reset token for the currently logged-in user viewing the page. This makes it possible for authenticated attackers, with Contributor-level access and above, to craft a malicious pending post that, when previewed by an Administrator, generates a password reset token for the Administrator and exfiltrates it to an attacker-controlled server, leading to full account takeover.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-285: Improper Authorization

Reaching this weakness in Ultimate Member <= 2.11.2 takes an account at Contributor level or above. Improper authorization means a permission check exists but does not cover the case being exercised, so a caller who is allowed to do one thing is allowed to do a neighbouring thing as well.

A lower-privileged account performs an action reserved for a higher one, which on a multi-author or membership site means an ordinary user reaching administrative behaviour. For Ultimate Member the fix is 2.11.3: builds <= 2.11.2 are affected, anything from 2.11.3 onward is not.

Remediation

Update to version 2.11.3, 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: Ultimate Member 2.11.3 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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