medium5.3
CVE-2026-41128
Craft CMS has a Missing Authorization Check on User Group Removal via save-permissions Action
Impact
Craft CMS is a content management system (CMS). In versions 5.6.0 through 5.9.14, the `actionSavePermissions()` endpoint allows a user with only `viewUsers` permission to remove arbitrary users from all user groups. While `_saveUserGroups()` enforces per-group authorization for additions, it performs no equivalent authorization check for removals, so submitting an empty `groups` value removes all existing group memberships. Version 5.9.15 contains a patch.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | craftcms/cms | >= 5.6.0, < 5.9.15 | 5.9.15 |