WWBN AVideo is an open source video platform. In versions up to and including 26.0, the `categories.json.php` endpoint, which serves the category listing API, fails to enforce user group-based access controls on categories. In the default request path (no `?user=` parameter), user group filtering is entirely skipped, exposing all non-private categories including those restricted to specific user groups. When the `?user=` parameter is supplied, a type confusion bug causes the filter to use the admin user's (user_id=1) group memberships instead of the current user's, rendering the filter ineffective. Commit 6e8a673eed07be5628d0b60fbfabd171f3ce74c9 contains a fix.

Affected: Packagist: wwbn/avideo

## Summary

The `categories.json.php` endpoint, which serves the category listing API, fails to enforce user group-based access controls on categories. In the default request path (no `?user=` parameter), user group filtering is entirely skipped, exposing all non-private categories including those restricted to specific user groups. When the `?user=` parameter is supplied, a type confusion bug causes the filter to use the admin user's (user_id=1) group memberships instead of the current user's, rendering the filter ineffective.

## Details

The vulnerability has two related failures in `objects/categories.json.php` and `objects/category.php`:

**1. Default request — group filtering completely skipped**

In `categories.json.php:17-24`, when `$_GET['user']` is not set, `$sameUserGroupAsMe` defaults to `false`:

```php // categories.json.php:17-24 $onlyWithVideos = false; $sameUserGroupAsMe = false; if(!empty($_GET['user'])){ $onlyWithVideos = true; $sameUserGroupAsMe = true; } $categories = Category::getAllCategories(true, $onlyWithVideos, false, $sameUserGroupAsMe); ```

In `category.php:438-452`, the user group filter is gated on `$sameUserGroupAsMe` being truthy:

```php // category.php:438-452 if ($sameUserGroupAsMe) { $users_groups = UserGroups::getUserGroups($sameUserGroupAsMe); $users_groups_id = array(0); foreach ($users_groups as $value) { $users_groups_id[] = $value['id']; } $sql .= " AND (" . "(SELECT count(*) FROM categor…