CVE-2026-90907

Analyzed Analyzed - Analysis Complete

Unauthorized User Account Creation in Joomla Core

Publication date: 2026-09-29

Last updated on: 2026-10-06

Assigner: Joomla! Project

Description

Joomla! Core - [20260902] - Core - Unauthorized user account creation via profile.save controller in Joomla 1.5.0-5.4.8, 6.0.0-6.1.3 - The profile.save controller did not check the login state of a user, allowing the creation of guest-level users on sites without active user registration.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-29

Last Modified

2026-10-06

Generated

2026-10-19

AI Q&A

2026-09-29

EPSS Evaluated

2026-10-18

NVD

CVE-2026-90907

EUVD

EUVD-2026-89085

Affected Vendors & Products

Vendor	Product	Version / Range
joomla	joomla!	From 6.0.0 (inc) to 6.1.3 (exc)
joomla	joomla!	From 1.5.0 (inc) to 5.4.8 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-639	The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

Attack-Flow Graph

Executive Summary

CVE-2026-90907 is an authorization bypass vulnerability in Joomla! CMS versions 1.5.0-5.4.8 and 6.0.0-6.1.3. It allows unauthorized creation of guest-level user accounts through the profile.save controller, even when user registration is disabled on the site.

Detection Guidance

Check Joomla version by inspecting the administrator/components/com_admin/version.php file or via the Joomla admin panel under System Information. Look for unauthorized guest accounts in Users > Manage > User Manager. Review server logs for suspicious profile.save controller requests.

Impact Analysis

This vulnerability could allow attackers to create unauthorized user accounts on your Joomla site. This may lead to unauthorized access, potential data manipulation, or further exploitation of your site's resources if not patched.

Compliance Impact

This vulnerability allows unauthorized user account creation, which could lead to unauthorized access to sensitive data. For GDPR, this may violate principles of data protection and user consent. For HIPAA, it could result in unauthorized access to protected health information, compromising compliance with security requirements.

Mitigation Strategies

Upgrade Joomla to version 5.4.9 or 6.1.4 immediately. If upgrading is not possible, disable the profile.save controller or restrict access to it via .htaccess rules. Monitor user accounts for unauthorized guest-level entries and remove any suspicious accounts.

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