What is CVE-2021-26040?

CVE-2021-26040 is a critical-severity vulnerability in Joomla Joomla\!, classified under Incorrect Authorization. CVSS score: 9.1/10. Published 2021-08-24.

How severe is CVE-2021-26040?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Auth bypass in Joomla Joomla\!

CVE-2021-26040

An issue was discovered in Joomla! 4.0.0. The media manager does not correctly check the user's permissions before executing a file deletion command.

Vulnerability class: Broken Access Control

Published 2021-08-24 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (59.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.3% 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: 0.009 · change: 0.000

Affected products

Joomla Joomla\! — versions 4.0.0
Joomla! Project Cms — versions 4.0.0

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

developer.joomla.org/security-centre/861-20210801-core-insufficient-access-cont… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-26040?: CVE-2021-26040 is a critical-severity vulnerability in Joomla Joomla\!, classified under Incorrect Authorization. CVSS score: 9.1/10. Published 2021-08-24.
How severe is CVE-2021-26040?: Critical severity. CVSS v3 base score is 9.1 out of 10.