CVE-2026-40488: OpenMage LTS: Customer File Upload Extension Blocklist Bypass → Remote Code Execution

April 21, 2026 (updated April 27, 2026)

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.

References

github.com/OpenMage/magento-lts
github.com/OpenMage/magento-lts/security/advisories/GHSA-3j5q-7q7h-2hhv
github.com/advisories/GHSA-3j5q-7q7h-2hhv
nvd.nist.gov/vuln/detail/CVE-2026-40488

Code Behaviors & Features

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