CVE-2026-104671

TutorStarter <= 4.0.3 - Unauthenticated Unauthorized User Account Creation

2026-10-06 00:00

Strategic Overview

Status: Patched in 4.0.4
Affected Theme: TutorStarter
Affected Version: <= 4.0.3
CVSS: 5.3Medium
Weakness type: CWE-306 · Missing Authentication for Critical Function
CVE: CVE-2026-104671

At a glance

CVE-2026-104671 is a medium-severity Missing Authentication for Critical Function vulnerability in the TutorStarter WordPress theme, affecting versions <= 4.0.3. 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 4.0.4; sites on affected versions should update now. Disclosed October 2026, reported by Alexander Jurkschat.

Vulnerability Overview

The TutorStarter theme for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 4.0.3. This is due to missing check against the site's users_can_register option in the wp_ajax_nopriv_ajaxregister AJAX handler. This makes it possible for unauthenticated attackers to register new WordPress user accounts even when user registration has been disabled by the site administrator.

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-306: Missing Authentication for Critical Function

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

Remediation

Update to version 4.0.4, 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: TutorStarter 4.0.4 closes this, and updating the theme is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-104671 https://www.wordfence.com/threat-intel/vulnerabilities/id/15909c21-4286-4572-85b4-909a6167313e https://nvd.nist.gov/vuln/detail/CVE-2026-104671

CVSS Vector

5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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