CVE-2026-48954 Joomla! Core - [20260708] - XSS through language overrides

Medium 5.9 Published Updated

Attackers can inject malicious scripts via language overrides, potentially stealing user sessions or executing code in Joomla CMS.

Exploited in the wild
Not known
Login needed
An administrator
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-48954?

CVE-2026-48954 is a medium-severity cross-site scripting vulnerability in Joomla Joomla\!, published on 7 Jul 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

Improper validation leads to a generic XSS vector in the language override feature.

Weakness: CWE-79

Which versions are affected by CVE-2026-48954?

1 open source package ship an affected version, including joomla. It affects 1 product.

PackageAffectedFixed in
joomla BitnamiFrom 3.0.05.4.7, 6.1.2

Products include Joomla Joomla\!.

How do I fix CVE-2026-48954?

Upgrade joomla to a fixed version for your release line: 5.4.7 or 6.1.2.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-48954 being exploited?

There is no known exploitation of CVE-2026-48954 in the wild and no public exploit code.

All Joomla Joomla\! vulnerabilities

Sources

Also known as BIT-joomla-2026-48954, GHSA-2hjh-jp76-w6fv.

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