CVE-2026-18421 Concrete CMS 9.0.0-9.5.2 Boards data source dashboard is missing an authorization check, allowing a low-privileged board editor to modify or delete configured data sources on boards they do not control

Concrete CMS 9 through 9.5.2 does not perform an authorization check in three actions of the Boards data source dashboard controller update, updatedatasource, and deletedatasource, which resolve a ConfiguredDataSource directly from an attacker-supplied identifier without confirming the requester'...

CVE-2026-9859

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-2026-9859

Mattermost Boards plugin (versions ≤11.7.6, ≤10.11.21, ≤11.8.3) fails to enforce PermissionManageBoardRoles on the batch endpoint's channelId field, allowing authenticated board editors to relink boards to arbitrary channels via crafted PATCH requests. CVSS 3.1 scores 6.5 (MEDIUM) for network-bas...

CVE-2026-9859: Incorrect Authorization

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...

PT-2026-76877

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.7.0 through 11.7.6 Mattermost versions 10.11.0 through 10.11.21 Mattermost versions 11.8.0 through 11.8.3 Description The Boards plugin fails to enforce the PermissionManageBoardRoles authorization on the channelId field...