High

OpenMage LTS has Customer File Upload Extension Blocklist Bypass that Leads to Remote Code Execution

Type: advisorySources: OSV

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.

Products: Not specified
Affected versions: Not specified
Fixed versions: Not specified
CVEs: CVE-2026-40488
Confirmed fixed CVEs: Not specified
Updated in this feed: 5 Nov 2026, 16:54 UTC · Revision 1

Source evidence

OpenMage LTS has Customer File Upload Extension Blocklist Bypass that Leads to Remote Code Execution

core-osv · Original source

Published 20 Apr 2026, 16:23 UTC

osv:CVE-2026-40488

Complete source record

{
  "id": "059ef9756438fd698f44de4fc43a904e4f544b25802514c6fdda1bef1ab63630",
  "url": "https://osv.dev/vulnerability/CVE-2026-40488",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "OpenMage LTS has Customer File Upload Extension Blocklist Bypass that Leads to Remote Code Execution",
    "summary": "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.",
    "evidence": "osv:CVE-2026-40488",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-40488",
      "aliases": [
        "CVE-2026-40488",
        "GHSA-3j5q-7q7h-2hhv"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/openmage/magento-lts",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "f4dd542b878613b9f40f39e9d7e862dec085defd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "20.17.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:openmage:magento:*:*:*:*:lts:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "20.17.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v20.16.0",
            "v20.15.0",
            "v20.14.0",
            "v20.13.0",
            "v20.12.2",
            "v20.12.1",
            "v20.12.0",
            "v20.11.0",
            "v20.10.1",
            "v21.0.0-beta2",
            "v20.10.0",
            "v20.9.0",
            "v20.8.0",
            "v20.7.0",
            "v20.6.0",
            "v20.5.0",
            "v20.4.0",
            "v20.3.0",
            "v20.2.0",
            "v20.1.1",
            "v20.1.0",
            "v20.1.0-rc7",
            "v20.1.0-rc6",
            "v20.1.0-rc5",
            "v20.1.0-rc4",
            "v20.1.0-rc3",
            "v20.1.0-rc2",
            "v20.1.0-rc1",
            "v20.0.18",
            "v20.0.17",
            "v20.0.16",
            "v20.0.15",
            "v20.0.13",
            "v20.0.12",
            "v20.0.11",
            "v20.0.10",
            "v20.0.8",
            "v20.0.7",
            "v20.0.6",
            "v20.0.5",
            "v20.0.4",
            "v20.0.3",
            "v20.0.2",
            "v20.0.1",
            "v20.0.0",
            "v19.4.4",
            "v19.4.3",
            "v19.4.2",
            "v19.4.1",
            "v19.4.0",
            "1.9.0.1",
            "1.9.1.1",
            "1.9.1.0-lts",
            "1.9.0.0",
            "1.8.1.0",
            "1.7.0.2",
            "1.7.0.1",
            "1.7.0.0",
            "1.6.1.0",
            "1.6.0.0",
            "1.6.0.0-rc2",
            "1.6.0.0-rc1",
            "1.6.0.0-beta1",
            "1.6.0.0-alpha1",
            "1.5.1.0",
            "1.5.0.1",
            "1.5.0.0",
            "1.5.0.0-rc2",
            "1.5.0.0-rc1",
            "1.5.0.0-beta2",
            "1.5.0.0-beta1",
            "1.5.0.0-alpha2",
            "1.5.0.0-alpha1",
            "1.4.2.0",
            "1.4.1.1",
            "1.4.1.0",
            "1.4.0.1",
            "1.3.2.4",
            "1.4.0.0",
            "1.4.0.0-rc1",
            "1.4.0.0-beta1",
            "1.4.0.0-alpha3",
            "1.4.0.0-alpha2",
            "1.4.0.0-alpha1",
            "1.3.2.3",
            "1.3.2.2",
            "1.3.2.1",
            "1.3.2",
            "1.3.1.1",
            "1.3.1",
            "1.3.0",
            "1.2.1.2",
            "1.2.1",
            "1.2.0.3",
            "1.2.0.2",
            "1.2.0.1",
            "1.2.0",
            "1.1.8",
            "1.1.7",
            "1.1.6",
            "1.1.5",
            "1.1.4",
            "1.1.3",
            "1.1.2",
            "1.1.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40488.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:44.491414539Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40488.json",
        "https://github.com/OpenMage/magento-lts/security/advisories/GHSA-3j5q-7q7h-2hhv",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-40488"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-434"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40488.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-40488",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 512476,
  "published_at": "2026-04-20T16:23:07.429+00:00"
}