[20260802] - Core - Improper CORS origin validation

Project: Joomla!
SubProject: CMS
Impact: Moderate
Severity: Moderate
Probability: Moderate
Versions: 4.0.0-5.4.7, 6.0.0-6.1.2
Exploit type: Improper CORS Origin Validation
Reported Date: 2026-07-09
Fixed Date: 2026-08-18
CVE Number: CVE-2026-71573

Description

An improper implementation prevented configured CORS origins from being properly validated in CORS requests.

Affected Installs

Joomla! CMS versions 4.0.0-5.4.7, 6.0.0-6.1.2

Solution

Upgrade to version 5.4.8, 6.1.3

Contact

The JSST at the Joomla! Security Centre.

Reported By: Agamemnon Fakas, caveeroo