Mattermost Incorrect Authorization vulnerability

Mattermost versions 10.5.x = 10.5.1, 10.4.x = 10.4.3, 9.11.x = 9.11.9 fail to check the "Allow Users to View Archived Channels" configuration when fetching channel metadata of a post from archived channels, which allows authenticated users to access such information when a channel is archived...

CVE-2025-27571 Channel metadata visible in archived channels despite configuration setting

Mattermost versions 10.5.x = 10.5.1, 10.4.x = 10.4.3, 9.11.x = 9.11.9 fail to check the "Allow Users to View Archived Channels" configuration when fetching channel metadata of a post from archived channels, which allows authenticated users to access such information when a channel is archived...

CVE-2025-27571 Channel metadata visible in archived channels despite configuration setting

Mattermost versions 10.5.x = 10.5.1, 10.4.x = 10.4.3, 9.11.x = 9.11.9 fail to check the "Allow Users to View Archived Channels" configuration when fetching channel metadata of a post from archived channels, which allows authenticated users to access such information when a channel is archived...