Craft CMS: Sensitive File Disclosure / Server-Side File Read

{
  "id": "29ecd48e2c0242fbf0044ac1bfc4d9e3dff88546de43fdf0358aaa13fae9f6a9",
  "url": "https://osv.dev/vulnerability/CVE-2026-55792",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Craft CMS: Sensitive File Disclosure / Server-Side File Read",
    "summary": "Craft CMS is a content management system (CMS). In versions starting from 4.0.0-RC1 and prior to 4.18.0, and 5.0.0-RC1 and above, prior to 5.10.0, the dataUrl() Twig function is included in Craft’s Twig sandbox allowlist, allowing any control panel user granted the utility:system-messages permission to embed a file-reading payload into system email templates. When those emails are sent, the server reads the target file and returns its contents as a base64-encoded data URL embedded in the email body. The .env file, which typically contains the database password, CRAFT_SECURITY_KEY, and third-party API keys, passes all of Craft’s existing dataUrl() protection checks and is fully exfiltrated. Obtaining CRAFT_SECURITY_KEY enables an attacker to forge session tokens and escalate to full admin account takeover. This issue has been fixed in versions 4.18.0 and 5.10.0.",
    "evidence": "osv:CVE-2026-55792",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-55792",
      "aliases": [
        "CVE-2026-55792",
        "GHSA-287w-mxq6-x2cp"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/craftcms/cms",
              "type": "GIT",
              "events": [
                {
                  "introduced": "daac7c1da2f701f2e9ddee1da1457ce61660b581"
                },
                {
                  "fixed": "f7fbf335ac15665372670b61046032f5f404f69a"
                },
                {
                  "introduced": "04755d93f86d07cc183db47db8a0eee106892e30"
                },
                {
                  "fixed": "a516a6190ba8ef39a7603863df9ae09eb89f3a64"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4.0.0-RC1"
                      },
                      {
                        "fixed": "4.18.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "5.0.0-RC1"
                      },
                      {
                        "fixed": "5.10.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55792.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.631372693Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55792.json",
        "https://github.com/craftcms/cms/security/advisories/GHSA-287w-mxq6-x2cp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-55792",
        "https://github.com/craftcms/cms/pull/18559"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-200"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55792.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-55792",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 518111,
  "published_at": "2026-07-01T23:20:28.993+00:00"
}