OpenMage LTS: Customer File Upload Extension Blocklist Bypass → Remote Code Execution

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

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 · score source

EPSS

• CVE-2026-40488: 0.69% estimated exploitation activity in the next 30 days; percentile 52.86 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

The product custom option file upload in OpenMage LTS uses an incomplete blocklist (forbiddenextensions = 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/customoptions/quote/ directory, which lacks server-side execution restrictions for some configurations, enabling Remote Code Execution if this directory is not explicitly denied script execution. Affected Version - Project: OpenMage/magento-lts - Vulnerable File: https://github.com/OpenMage/magento-lts/blob/main/app/code/core/Mage/Catalog/Model/Product/Option/Type/File.php - Vulnerable Lines: 230-237 (validateUploadedFile()) - Configuration: app/code/core/Mage/Catalog/etc/config.xml:824 Root Cause The file upload handler uses ZendFileTransferAdapterHttp directly with ExcludeExtension validator, referencing only: This misses the comprehensive…

Published by the source

21 Apr 2026, 18:53 UTC

Last modified by the source

27 Apr 2026, 16:31 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3j5q-7q7h-2hhv

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# Patch Next advisory brief: CVE-2026-40488

Advisory: OpenMage LTS: Customer File Upload Extension Blocklist Bypass → Remote Code Execution
IDs: CVE-2026-40488, GHSA-3j5q-7q7h-2hhv
Record: https://patchnext.com/advisories/cve-2026-40488 (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: openmage/magento-lts 20.17.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist openmage/magento-lts: affected <= 20.16.0; fixed in 20.17.0

## Suggested inspection (read-only)
- Packagist openmage/magento-lts: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on openmage/magento-lts.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-3j5q-7q7h-2hhv (GitHub-reviewed advisory GHSA-3j5q-7q7h-2hhv lists affected ranges: Packagist openmage/magento-lts >=0 <=20.16.0)

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