CVE-2026-90913: 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

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-29 · updated 2026-10-06
Weakness: CWE-284

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.

Affected products

Joomla!: from 4.0.0 before 5.4.8; from 6.0.0 before 6.1.3 — fixed in 5.4.8, 6.1.3

How to fix

Upgrade to a fixed version: Joomla! 5.4.8, 6.1.3. Check the vendor advisory for mitigations.

References

https://developer.joomla.org/security-centre/1083-20260903-core-improper-acl-checks-for-user-level-webservice-endpoints.html
https://www.joomla.org/

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