What is CVE-2021-26027?

CVE-2021-26027 is a medium-severity vulnerability in Joomla Joomla\!, classified under Incorrect Authorization. CVSS score: 5.3/10. Published 2021-03-04.

How severe is CVE-2021-26027?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Auth bypass in Joomla Joomla\!

CVE-2021-26027

An issue was discovered in Joomla! 3.0.0 through 3.9.24. Incorrect ACL checks could allow unauthorized change of the category for an article.

Vulnerability class: Broken Access Control

Published 2021-03-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.010 (59.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 59.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.010 · change: +0.000

Affected products

Joomla Joomla\!
Joomla! Project Cms — versions 3.0.0-3.9.24

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

developer.joomla.org/security-centre/847-20210307-core-acl-violation-within-com… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-26027?: CVE-2021-26027 is a medium-severity vulnerability in Joomla Joomla\!, classified under Incorrect Authorization. CVSS score: 5.3/10. Published 2021-03-04.
How severe is CVE-2021-26027?: Medium severity. CVSS v3 base score is 5.3 out of 10.