CVE-2026-90918: Joomla!

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

Joomla! Core - [20260908] - Core - XSS in HTML Mail Templates in Joomla 4.0.0-5.4.8, 6.0.0-6.1.3 - The mail template feature lacks an escaping mechanism, causing XSS vectors in multiple extensions.

Affected products

• Joomla! Joomla!: from 4.0.0, before 5.4.8 (fixed in 5.4.8); from 6.0.0, before 6.1.3 (fixed in 6.1.3)

Published 2026-09-29. Last modified 2026-10-06.