CVE-2025-49222: Unrestricted Upload of File with Dangerous Type

Mattermost versions 10.8.x = 10.8.3, 10.5.x = 10.5.8, 9.11.x = 9.11.17, 10.9.x = 10.9.2, 10.10.x = 10.10.0 fail to validate upload types in remote cluster upload sessions which allows a system admin to upload non-attachment file types via shared channels that could potentially be placed in...