CVE-2026-9859 Mattermost Boards plugin didn’t enforce role-based authorization on board channel link allowing board editors to expose boards to arbitrary channels

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21, 11.8.x = 11.8.3 fail to enforce PermissionManageBoardRoles on the channelId field of the batch endpoint, which allows an authenticated board editor to relink any board they can edit to an arbitrary channel via a crafted PATCH request...

CVE-2026-16047 Board channel linking without read channel permission validation

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21, 11.8.x = 11.8.3 fail to validate that users have read access to a channel before linking a board to it, which allows an authenticated attacker to discover the membership of private channels on the same team via creating, patching, importing...

EUVD-2023-44232

Malicious code in bioql PyPI...

CVE-2024-32045

Mattermost versions 9.5.x = 9.5.3, 9.6.x = 9.6.1, 8.1.x = 8.1.12 fail to enforce proper access controls for channel and team membership when linking a playbook run to a channel which allows members to link their runs to private channels they were not members of...