What is CVE-2024-21726?

CVE-2024-21726 is a medium-severity vulnerability in Joomla Joomla\!, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2024-02-29.

How severe is CVE-2024-21726?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Is CVE-2024-21726 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Joomla Joomla\!

CVE-2024-21726

Inadequate content filtering leads to XSS vulnerabilities in various components.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2024-02-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L.

EPSS exploit prediction

EPSS: 0.488 (98.8th percentile), scored 2026-09-27.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 99th percentile — 98.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.488 · newest: 0.488 · change: 0.000

Affected products

Joomla Joomla\!
Joomla! Project Cms — versions 3.7.0-3.10.14, 4.0.0-4.4.2, 5.0.0-5.0.2

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

developer.joomla.org/security-centre/929-20240205-core-inadequate-content-filte… (vendor-advisory, Vendor Advisory)
www.sonarsource.com/blog/joomla-multiple-xss-vulnerabilities/ (Exploit, technical-description, Third Party Advisory)

Frequently asked questions

What is CVE-2024-21726?: CVE-2024-21726 is a medium-severity vulnerability in Joomla Joomla\!, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2024-02-29.
How severe is CVE-2024-21726?: Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2024-21726 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.