CVE-2026-21631 MEDIUM

CVE-2026-21631: Joomla! Core - [20260303] - XSS vector in com_associations comparison view

Vendor Joomla! Project
Product Joomla! CMS
Weakness CWE-79 · XSS
Published April 1, 2026
Last update April 2, 2026
View on NVD All CVEs

CVSS base score

5.9/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction —
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:U

What the vulnerability does

01Description

Lack of output escaping leads to a XSS vector in the multilingual associations component.

Explanation of Vulnerability in Simple Terms

02Summary

Joomla! CMS versions 4.0.0 through 5.4.3 contain a cross-site scripting (XSS) vulnerability that allows authenticated users with high privileges to inject malicious scripts. An attacker must have administrative-level access and trick a user into visiting a crafted page. The injected script executes in the victim's browser, potentially compromising their session or stealing sensitive data.

What an attacker can do

03Attacker Capabilities

Inject and execute malicious JavaScript in a victim's browser session.

Potential impact on your site

04Site Impact

Administrators could be compromised if tricked into visiting attacker-controlled pages, risking site takeover or data theft.

Conditions required to exploit

05Prerequisites

Attacker needs high-level admin access and victim must click a malicious link or visit a crafted page.

Key dates

06Disclosure timeline

April 1, 2026 CVE published
April 2, 2026 Record updated

Related vulnerabilities

08Related CVE

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