CVE-2026-17563

User Frontend <= 4.3.10 - Missing Authorization to Unauthenticated Post Creation

2026-08-31 00:00
Charles Vosburgh

Strategic Overview

Status
Patched in 4.3.11
Affected Plugin
User Frontend – Membership, User Registration, User Profile, User Directory & Content Restriction with Frontend Post Submission
Affected Version
<= 4.3.10
CVSS
5.3Medium
Weakness type
CWE-862 · Missing Authorization
CVE
CVE-2026-17563
View all User Frontend – Membership, User Registration, User Profile, User Directory & Content Restriction with Frontend Post Submission vulnerabilities

At a glance

CVE-2026-17563 is a medium-severity Missing Authorization vulnerability in the User Frontend WordPress plugin, affecting versions <= 4.3.10. 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 4.3.11; sites on affected versions should update now. Disclosed August 2026, reported by Charles Vosburgh.

Vulnerability Overview

The User Frontend plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.3.10. This is due to missing server-side enforcement of the form's subscription gate in the AJAX post-submission handler, which only checked the gate at render time. This makes it possible for unauthenticated attackers to create posts through subscription-gated frontend forms without purchasing a subscription, bypassing payment requirements entirely.

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-862: Missing Authorization

Reaching this weakness in User Frontend <= 4.3.10 takes no account at all. 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 Frontend the fix is 4.3.11: builds <= 4.3.10 are affected, anything from 4.3.11 onward is not.

Remediation

Update to version 4.3.11, 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 Frontend 4.3.11 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-17563https://www.wordfence.com/threat-intel/vulnerabilities/id/d60e9835-63ec-4f31-b247-e92561f9007bhttps://nvd.nist.gov/vuln/detail/CVE-2026-17563

Related records

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