GHSA-mpmw-f6h6-3g26 is a medium-severity (CVSS 4.3) vulnerability in winter/wn-backend-module. O3 Security confirms whether GHSA-mpmw-f6h6-3g26 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Winter: My Account preview exposes another backend user's profile by record ID
Real-World Exposure
winter/wn-backend-moduleReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
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.
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:
GET /backend/backend/myaccount/preview/{other_user_id}
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.
The 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.
To actively exploit this security issue, an attacker would need access to the Backend with a user account with any level of access.
Patches
MyAccount no longer exposes the generic record actions it never used as routes, and its form lookup is now pinned to the authenticated user:
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.formExtendQuery()constrains every lookup made by the behavior to the current user's key.
This security issue has been fixed as of v1.2.14 (commit cdbc8f5a23db27f72ccec658a8e5769e6d9f6dcb).
Workarounds
There is no supported workaround other than upgrading. If you cannot upgrade immediately, you may apply the fix manually in modules/backend/controllers/MyAccount.php:
- Add
protected $guarded = ['create', 'update', 'preview'];to the controller. - Add a
formExtendQuery()method that scopes the lookup to the current user:
public function formExtendQuery(\Winter\Storm\Database\Builder $query): void
{
$query->whereKey($this->user->getKey());
}
References
- https://github.com/wintercms/winter/security/advisories/GHSA-j5jq-cr68-v2xx
- https://github.com/wintercms/winter/commit/cdbc8f5a23db27f72ccec658a8e5769e6d9f6dcb
Credit to Awwader (@NRAwwad) for reporting the issue.
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | winter/wn-backend-module | ≥ 1.2.13&&< 1.2.14 | 1.2.14 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for winter/wn-backend-module. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update winter/wn-backend-module to 1.2.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mpmw-f6h6-3g26 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-mpmw-f6h6-3g26 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-mpmw-f6h6-3g26. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-mpmw-f6h6-3g26 in your dependencies?
O3 detects GHSA-mpmw-f6h6-3g26 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.