Improper Authorization

Mattermost is vulnerable to an Improper Authorization. The vulnerability is due to insufficient enforcement of channel conversion restrictions due to a flaw that allows users with permission to convert public channels to private ones to also convert private channels to public...

CVE-2025-27933

Mattermost versions 10.4.x = 10.4.2, 10.3.x = 10.3.3, 9.11.x = 9.11.8 fail to fail to enforce channel conversion restrictions, which allows members with permission to convert public channels to private ones to also convert private ones to public...

CVE-2025-27933 Unauthorized Private-to-Public Channel Conversion

Mattermost versions 10.4.x = 10.4.2, 10.3.x = 10.3.3, 9.11.x = 9.11.8 fail to fail to enforce channel conversion restrictions, which allows members with permission to convert public channels to private ones to also convert private ones to public...