Arbitrary file upload in magento-lts - #VU158611
Published: November 2, 2026
Vulnerability identifier: #VU158611
CSH Severity: Medium
CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-434
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary script in a victim's browser within the store's origin.
The vulnerability exists due to unrestricted upload of files with dangerous types in Mage_Catalog_Model_Product_Option_Type_File::_validateUploadedFile() when a product File custom option has an empty allowed-extension list and the web server serves media/custom_options/. A remote attacker can upload a crafted SVG, XHTML, or XML document and trick a victim into opening its URL to execute arbitrary script in the store's origin.
Affected software
magento-lts
Remediation
Install security update from vendor's website.
magento-lts - addressed in versions 20.18.2, 20.19.0, 21.0.0 beta3