Arbitrary file upload in Joomla! - CVE-2026-73373
Published: August 18, 2026
Vulnerability identifier: #VU144193
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-73373
CWE-ID: CWE-434
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to unrestricted upload of file with dangerous type in the file upload functionality when uploading SHTML files to a server that executes these files. A remote user can upload a specially crafted SHTML file to execute arbitrary code.
Exploitation depends on the server being configured to execute SHTML files.
Affected software
Joomla!
How to mitigate CVE-2026-73373
Install security update from vendor's website.
Joomla! - addressed in versions 5.4.8, 6.1.3