CVE-2026-40488

CVE-2026-40488 is a high-severity vulnerability in Openmage Magento with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-434.

Key facts

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.

Frequently asked questions

What is CVE-2026-40488?
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.
How severe is CVE-2026-40488?
CVE-2026-40488 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40488 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40488?
CVE-2026-40488 affects Openmage Magento. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40488?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40488 have an EU (EUVD) identifier?
Yes. CVE-2026-40488 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23904.
When was CVE-2026-40488 published?
CVE-2026-40488 was published on 2026-04-20 and last updated on 2026-06-17.

References

Affected products (1)

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