What’s Vulnerable › Vulnerabilities
CVE-2026-40488: OpenMage LTS has Customer File Upload Extension Blocklist Bypass that Leads to Remote Code Execution
- Severity: high (CVSS 8.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.7% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-04-20 · updated 2026-10-26
- Weakness: CWE-434
Description
Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a high level of backward compatibility. Prior to version 20.17.0, the product custom option file upload in OpenMage LTS uses an incomplete blocklist (`forbidden_extensions = php,exe`) to prevent dangerous file uploads. This blocklist can be trivially bypassed by using alternative PHP-executable extensions such as `.phtml`, `.phar`, `.php3`, `.php4`, `.php5`, `.php7`, and `.pht`. Files are stored in the publicly accessible `media/custom_options/quote/` directory, which lacks server-side execution restrictions for some configurations, enabling Remote Code Execution if this directory is not explicitly denied script execution. Version 20.17.0 patches the issue.
Affected products
- OpenMage magento-lts: before 20.17.0 — fixed in 20.17.0
How to fix
Upgrade to a fixed version: OpenMage magento-lts 20.17.0. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-40488 or the next vulnerability affects your stack