CVE-2026-21631 Joomla! Core - [20260303] - XSS vector in com_associations comparison view
Attackers can inject malicious scripts via the multilingual associations comparison view, 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-2026-21631?
CVE-2026-21631 is a medium-severity cross-site scripting vulnerability in Joomla Joomla\!, published on 1 Apr 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
Lack of output escaping leads to a XSS vector in the multilingual associations component.
Weakness: CWE-79
Which versions are affected by CVE-2026-21631?
1 open source package ship an affected version, including joomla. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
joomla Bitnami | From 3.0.0 | 5.4.4, 6.0.4 |
Products include Joomla Joomla\!.
How do I fix CVE-2026-21631?
Upgrade joomla to a fixed version for your release line: 5.4.4 or 6.0.4.
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-2026-21631 being exploited?
There is no known exploitation of CVE-2026-21631 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-2026-21631, GHSA-24p2-2h4q-gmhf.