CVE-2026-21632 MEDIUM

CVE-2026-21632: Joomla! Core - [20260304] - XSS vectors in various article title outputs

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 for article titles leads to XSS vectors in various locations.

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 with administrative access can craft input that executes JavaScript in other users' browsers when they view affected pages. This requires user interaction—the victim must visit a page containing the injected payload.

What an attacker can do

03Attacker Capabilities

Inject JavaScript that runs in other users' browsers when they view affected pages.

Potential impact on your site

04Site Impact

A compromised admin account can inject scripts affecting other admins or users, potentially stealing sessions or credentials.

Conditions required to exploit

05Prerequisites

Attacker must have high-level administrative privileges and the victim must visit a page with the malicious payload.

Key dates

06Disclosure timeline

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

Related vulnerabilities

08Related CVE

CVE-2026-9626 JSON API User <= 4.1.0 - Authenticated (Subscriber+) Stored Cross-Site Scripting via 'content' Parameter CVE-2026-27408 WordPress NativeChurch theme <= 4.8.8.2 - Reflected Cross Site Scripting (XSS) vulnerability CVE-2026-27430 WordPress TheFox theme <= 3.9.76 - Reflected Cross Site Scripting (XSS) vulnerability CVE-2026-57754 WordPress Livemesh Addons for WPBakery Page Builder plugin <= 3.9.4 - Cross Site Scripting (XSS) vulnerability CVE-2026-8351 RTMKit <= 2.0.7 - Authenticated (Contributor+) Stored Cross-Site Scripting via Advanced Heading Widget 'Background Text' Parameter