CVE-2026-90918

Medium

Description

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.

SeverityMedium

CVSS5.3

Exploit probability—

Product

Joomla\!

PublishedSep 29, 2026

First seenSep 29, 2026

Weakness typeCWE-79Cross-site scripting (XSS)

How to fix

Update

joomla joomla\!5.4.8, 6.1.3 or later

Vendor advisories

developer.joomla.org/security-centre/1088-20260908-core-xss-in-html-mail-templates.html

Affected products

Product	Affected versions	Fixed in
joomla joomla\!	4.0.0 ≤ v < 5.4.8, 6.0.0 ≤ v < 6.1.3	5.4.8, 6.1.3

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

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