SUSE CVE-2026-4265

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to validate team-specific uploadfile permissions which allows a guest user to post files in channels where they lack uploadfile permission via uploading files in a team where they have permission and reusing the file...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via the upload process. An attacker can bypass team-specific file upload restrictions by uploading files in a team where they have permission and reusing the file metadata in a POST request to a different team...

EUVD-2026-12425

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to validate team-specific uploadfile permissions which allows a guest user to post files in channels where they lack uploadfile permission via uploading files in a team where they have permission and reusing the file...

CVE-2026-4265

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to validate team-specific uploadfile permissions which allows a guest user to post files in channels where they lack uploadfile permission via uploading files in a team where they have permission and reusing the file...

PT-2026-25705

Mattermost fails to validate team-specific upload file permissions in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If this is causing false-positive reports fr...