Mattermost Channel Conversion Restriction Bypass Vulnerability

A vulnerability exists in Mattermost versions 10.4.x through 10.4.2, 10.3.x through 10.3.3, and 9.11.x through 9.11.8, allowing users with permission to convert public channels to private ones to also convert private channels back to public. This issue arises from the application's failure to properly enforce channel conversion restrictions.

Impact

Exploitation of this vulnerability allows for unauthorized channel conversions, potentially leading to privacy breaches by exposing private channel content to the public.