{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "getgrav/grav"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.0.0-beta.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-611"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-05T21:35:53Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "Dear Grav Security Team,\n\nA security vulnerability was discovered in Grav CMS that allows authenticated attackers to read arbitrary files from the server through XML External Entity (XXE) injection.\n\n Vulnerability Summary\n\n| Field | Details |\n|-------|---------|\n| Vulnerability Type | XML External Entity (XXE) Injection |\n| Severity | High (CVSS 7.5) |\n| Affected Versions | Grav CMS \u003c= 1.7.x |\n| Affected Component | SVG file upload/processing |\n| CWE | CWE-611: Improper Restriction of XML External Entity Reference |\n| Authentication Required | Yes (Admin panel access) |\n\nTechnical Details\n\n Root Cause\nThe application uses `simplexml_load_string()` to process uploaded SVG files without disabling external entity loading. This allows attackers to inject XXE payloads that are processed by the XML parser.\n\n Vulnerable Code Pattern\n```php\n// Current (Vulnerable):\n$svg = simplexml_load_string($content);\n\n// No LIBXML_NOENT flag or entity loader protection\n```\n\n Attack Vector\n1. Attacker authenticates to Grav admin panel\n2. Uploads malicious SVG file via Pages \u2192 Media or File Manager plugin\n3. Server parses SVG and processes XXE entities\n4. Arbitrary file contents are exfiltrated\n\n Impact\n\nAn authenticated attacker can:\n\n1. Read sensitive files:\n   - `/etc/passwd` - System user information\n   - `user/accounts/*.yaml` - Admin credentials and 2FA secrets\n   - `user/config/system.yaml` - System configuration\n   - `.env` files - Environment secrets and API keys\n\n2. Perform SSRF - Access internal services via external entity URLs\n\n3. Potential DoS - Billion laughs attack via recursive entity expansion\n\nProof of Concept\n\n Malicious SVG Payload\n```xml\n\u003c?xml version=\"1.0\" encoding=\"UTF-8\"?\u003e\n\u003c!DOCTYPE svg [\n  \u003c!ENTITY xxe SYSTEM \"file:///etc/passwd\"\u003e\n]\u003e\n\u003csvg xmlns=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\"\u003e\n  \u003ctext x=\"10\" y=\"50\"\u003e\u0026xxe;\u003c/text\u003e\n\u003c/svg\u003e\n```\n\n Steps to Reproduce\n1. Login to Grav CMS admin panel\n2. Navigate to Pages \u2192 select any page \u2192 Media tab\n3. Upload the malicious SVG file\n4. Observe file contents in response/error or stored output\n\n Recommended Fix\n\n Option 1: Add XXE Protection Flags\n```php\nlibxml_use_internal_errors(true);\n$svg = simplexml_load_string($content, \u0027SimpleXMLElement\u0027, LIBXML_NOENT | LIBXML_DTDLOAD);\n```\n\n Option 2: Use SVG Sanitizer Library (Recommended)\n```php\nuse enshrined\\svgSanitize\\Sanitizer;\n\n$sanitizer = new Sanitizer();\n$sanitizer-\u003eremoveRemoteReferences(true);\n$cleanSVG = $sanitizer-\u003esanitize($content);\n```\n\nThe `enshrined/svg-sanitize` library properly strips XXE payloads and other malicious SVG content.\n\n Request\n\n1. Please acknowledge receipt of this report within 5 business days\n2. Please provide an estimated timeline for a security patch\n3. I am happy to assist with testing the fix\n4. I request a CVE be assigned for this vulnerability\n5. If you have a security advisory process, please include me in the credits\n\nTurki Almatrafi.\n\n\n\n---\n\n## Maintainer note \u2014 fix applied (2026-04-24)\n\nFixed across two repos:\n\n1. **Grav core on the `2.0` branch** (commit [`5a12f9be8`](https://github.com/getgrav/grav/commit/5a12f9be8), ships in **2.0.0-beta.2**) \u2014 `VectorImageMedium::__construct` (the code path that reads width/height from an uploaded SVG) now strips `\u003c!DOCTYPE\u003e` and `\u003c!ENTITY\u003e` declarations before parsing, and calls `simplexml_load_string` with `LIBXML_NONET | LIBXML_NOERROR | LIBXML_NOWARNING`. On PHP \u003c 8 it also calls `libxml_disable_entity_loader(true)` for the duration of the parse.\n\n2. **rhukster/dom-sanitizer** (commit [`02d08ec`](https://github.com/rhukster/dom-sanitizer/commit/02d08ec)) \u2014 the library Grav ships as its SVG sanitizer. `loadDocument` now applies the same DOCTYPE/ENTITY strip and passes `LIBXML_NONET` to `loadXML`/`loadHTML`.\n\nWith both layers in place, the PoC:\n\n```xml\n\u003c!DOCTYPE svg [\n  \u003c!ENTITY xxe SYSTEM \"file:///etc/passwd\"\u003e\n]\u003e\n\u003csvg xmlns=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\"\u003e\n  \u003ctext x=\"10\" y=\"50\"\u003e\u0026xxe;\u003c/text\u003e\n\u003c/svg\u003e\n```\n\nno longer expands `\u0026xxe;`, and the parser cannot make outbound filesystem or network requests for external entities/DTDs. Billion-laughs-style entity expansion is also neutralized because the declarations are stripped before libxml ever sees them.\n\n**Files:**\n- [`system/src/Grav/Common/Page/Medium/VectorImageMedium.php`](https://github.com/getgrav/grav/blob/2.0/system/src/Grav/Common/Page/Medium/VectorImageMedium.php).\n- [`tests/unit/Grav/Common/Security/SvgXxeSecurityTest.php`](https://github.com/getgrav/grav/blob/2.0/tests/unit/Grav/Common/Security/SvgXxeSecurityTest.php) \u2014 XXE neutralization + billion-laughs + plain-SVG regression.\n- dom-sanitizer: [`src/DOMSanitizer.php`](https://github.com/rhukster/dom-sanitizer/blob/main/src/DOMSanitizer.php) + two new XXE tests in its own suite.",
  "id": "GHSA-3446-6mgw-f79p",
  "modified": "2026-05-05T21:35:53Z",
  "published": "2026-05-05T21:35:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/getgrav/grav/security/advisories/GHSA-3446-6mgw-f79p"
    },
    {
      "type": "WEB",
      "url": "https://github.com/getgrav/grav/commit/5a12f9be8314682c8713e569e330f11805d0a663"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/getgrav/grav"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Grav is Vulnerable to XXE via SVG Upload "
}