CVE-2021-26032 [20210501] - Core - Adding HTML to the executable block list of MediaHelper::canUpload
Attackers can inject malicious HTML via file uploads due to missing block list entries, leading to cross-site scripting attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-26032?
CVE-2021-26032 is a medium-severity cross-site scripting vulnerability in Joomla Joomla\!, published on 26 May 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
An issue was discovered in Joomla! 3.0.0 through 3.9.26. HTML was missing in the executable block list of MediaHelper::canUpload, leading to XSS attack vectors.
Weakness: CWE-79
Which versions are affected by CVE-2021-26032?
1 open source package ship an affected version, including joomla. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
joomla Bitnami | From 3.0.0 to 3.9.26 | None |
Products include Joomla Joomla\!.
How do I fix CVE-2021-26032?
No fix has been published for CVE-2021-26032 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-26032 being exploited?
There is no known exploitation of CVE-2021-26032 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-2021-26032, GHSA-jjxj-55qc-vc28.