GHSA-mpmw-f6h6-3g26: Winter My Account Preview Exposes Another Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mpmw-f6h6-3g26",
  "modified" : "2026-08-20T18:44:45Z",
  "published" : "2026-08-20T18:44:45Z",
  "aliases" : [ ],
  "summary" : "Winter: My Account preview exposes another backend user's profile by record ID",
  "details" : "### Impact\n\n`Backend\\Controllers\\MyAccount`, introduced in v1.2.13, declares an empty `$requiredPermissions` array so that any authenticated backend user can manage their own account. It implements the `FormController` behavior, which exposes three routable actions — `create`, `update` and `preview` — that each take a record id from the URL.\n\n`index()` passes the authenticated user's own id to the behavior, but the inherited actions were left routable and `formFindModelObject()` was not scoped, so a caller-supplied id resolved against an unscoped `Backend\\Models\\User` query:\n\n```\nGET /backend/backend/myaccount/preview/{other_user_id}\n```\n\n`preview` disclosed the target user's first name, last name, login, email address and avatar; `update` was equally routable and additionally disclosed role, group membership, superuser flag and throttle state. Password controls render a mask, so no credential material was exposed. Backend user ids are sequential and trivially enumerated, and as these are `GET` actions no CSRF token is involved.\n\nThe behavior's AJAX handlers (`create_onSave`, `update_onSave`, `update_onDelete`) were also dispatchable on these routes, but cross-user writes were blocked by the `Backend\\Models\\User` authorization guards added in v1.2.13. The confirmed impact is unauthorized disclosure of backend user profile data.\n\nTo actively exploit this security issue, an attacker would need access to the Backend with a user account with any level of access.\n\n### Patches\n\n`MyAccount` no longer exposes the generic record actions it never used as routes, and its form lookup is now pinned to the authenticated user:\n\n- `protected $guarded = ['create', 'update', 'preview'];` removes the inherited actions from routing. The guard has to be at the routing layer, as handler dispatch (`{action}_{handler}`) runs before the page action.\n- `formExtendQuery()` constrains every lookup made by the behavior to the current user's key.\n\nThis security issue has been fixed as of **v1.2.14** (commit [`cdbc8f5a23db27f72ccec658a8e5769e6d9f6dcb`](https://github.com/wintercms/winter/commit/cdbc8f5a23db27f72ccec658a8e5769e6d9f6dcb)).\n\n### Workarounds\n\nThere is no supported workaround other than upgrading. If you cannot upgrade immediately, you may apply the fix manually in `modules/backend/controllers/MyAccount.php`:\n\n1. Add `protected $guarded = ['create', 'update', 'preview'];` to the controller.\n2. Add a `formExtendQuery()` method that scopes the lookup to the current user:\n\n```php\npublic function formExtendQuery(\\Winter\\Storm\\Database\\Builder $query): void\n{\n    $query->whereKey($this->user->getKey());\n}\n```\n\n### References\n\n- https://github.com/wintercms/winter/security/advisories/GHSA-j5jq-cr68-v2xx\n- https://github.com/wintercms/winter/commit/cdbc8f5a23db27f72ccec658a8e5769e6d9f6dcb\n\n\nCredit to Awwader ([@NRAwwad](https://github.com/NRAwwad)) for reporting the issue.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n- Email us at [hello@wintercms.com](mailto:hello@wintercms.com)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "winter/wn-backend-module"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.2.13"
      }, {
        "fixed" : "1.2.14"
      } ]
    } ],
    "versions" : [ "1.2.13" ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/wintercms/winter/security/advisories/GHSA-mpmw-f6h6-3g26"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wintercms/winter/commit/cdbc8f5a23db27f72ccec658a8e5769e6d9f6dcb"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/wintercms/winter"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wintercms/winter/releases/tag/v1.2.14"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-20T18:44:45Z",
    "nvd_published_at" : null
  }
}