CVE-2026-48903 Joomla! Framework - [20260519] - Inadequate content filtering within the checkAttribute filter code.
Inadequate content filtering in Joomla! Framework allows attackers to inject malicious scripts, potentially leading to session hijacking or code execution.
- 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-2026-48903?
CVE-2026-48903 is a medium-severity cross-site scripting vulnerability in Joomla Joomla\!, published on 26 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
Inadequate content filtering within the checkAttribute methods leads to XSS vulnerabilities in various components.
Weakness: CWE-79
Which versions are affected by CVE-2026-48903?
1 open source package ship an affected version, including joomla. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
joomla Bitnami | From 3.0.0 | 5.4.6, 6.1.1 |
Products include Joomla Joomla\!.
How do I fix CVE-2026-48903?
Upgrade joomla to a fixed version for your release line: 5.4.6 or 6.1.1.
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-2026-48903 being exploited?
There is no known exploitation of CVE-2026-48903 in the wild and no public exploit code.
Other vulnerabilities in Joomla Joomla\!
- CVE-2016-10033 PHPMailer Command Injection
- CVE-2023-23752 Joomla! Improper Access Control
- CVE-2026-48902 Joomla! Core - [20260518] - Transport encryption downgrade for password and username reset links
- CVE-2025-25226 [20250401] - Joomla Framework - SQL injection vulnerability in quoteNameStr method of Database package
- CVE-2022-23795 [20220303] - Core - User row are not bound to a authentication mechanism
Sources
Also known as BIT-joomla-2026-48903, GHSA-r82q-7896-84h5.