CVE-2021-26038 [20210704] - Core - Privilege escalation through com_installer
Attackers can escalate privileges via com_installer if ACLs are modified from defaults, requiring immediate patching for Joomla administrators.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-26038?
CVE-2021-26038 is a high-severity missing authorization vulnerability in Joomla Joomla\!, published on 7 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Install action in com_installer lack the required hardcoded ACL checks for superusers. A default system is not affected cause the default ACL for com_installer is limited to super users already.
Weakness: CWE-754
Which versions are affected by CVE-2021-26038?
1 open source package ship an affected version, including joomla. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
joomla Bitnami | From 2.5.0 to 3.9.27 | None |
Products include Joomla Joomla\!.
How do I fix CVE-2021-26038?
No fix has been published for CVE-2021-26038 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-26038 being exploited?
There is no known exploitation of CVE-2021-26038 in the wild and no public exploit code.
Other vulnerabilities in Joomla Joomla\!
- CVE-2016-10033 PHPMailer Command Injection
- CVE-2023-23752 Joomla! Improper Access Control
- CVE-2026-48902 Joomla! Core - [20260518] - Transport encryption downgrade for password and username reset links
- CVE-2025-25226 [20250401] - Joomla Framework - SQL injection vulnerability in quoteNameStr method of Database package
- CVE-2022-23795 [20220303] - Core - User row are not bound to a authentication mechanism
Sources
Also known as BIT-joomla-2021-26038, GHSA-jg45-rw63-37ww.