CVE-2026-90913 Missing authorization in Joomla! CMS
Unauthorized users can modify access levels via webservice endpoints due to improper ACL checks in Joomla Core.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90913?
CVE-2026-90913 is a high-severity missing authorization vulnerability in Joomla Joomla\!, published on 29 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
Joomla! Core - [20260903] - Core - Improper ACL checks for access level webservice endpoints in Joomla 4.0.0-5.4.8, 6.0.0-6.1.3 - An improper access check allows unauthorized users to perform mutation actions in access level endpoints.
Weakness: CWE-284
Which versions are affected by CVE-2026-90913?
1 open source package ship an affected version, including joomla. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
joomla Bitnami | From 4.0.0 | 5.4.8, 6.1.3 |
Products include Joomla Joomla\!.
How do I fix CVE-2026-90913?
Upgrade joomla to a fixed version for your release line: 5.4.8 or 6.1.3.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-90913 being exploited?
There is no known exploitation of CVE-2026-90913 in the wild and no public exploit code.
Other vulnerabilities in Joomla Joomla\!
- CVE-2016-10033 PHPMailer Command Injection
- CVE-2023-23752 Joomla! Improper Access Control
- CVE-2026-48902 Joomla! Core - [20260518] - Transport encryption downgrade for password and username reset links
- CVE-2025-25226 [20250401] - Joomla Framework - SQL injection vulnerability in quoteNameStr method of Database package
- CVE-2022-23795 [20220303] - Core - User row are not bound to a authentication mechanism
Sources
Also known as BIT-joomla-2026-90913, GHSA-g59x-9hwq-cm5h.