Inadequate checks had allowed users to modify the access levels of user groups with higher permissions.
This vulnerability affects the following application versions:
- Joomla 3.8.4
- Joomla 3.8.4-rc
- Joomla 3.8.4-rc2
- Joomla 3.8.5
- Joomla 3.8.5-rc
- Joomla 3.8.6
- Joomla 3.8.6-rc1
- Joomla 3.8.7
- Joomla 3.8.7-rc
- Joomla 3.8.8-rc