Mattermost Server 11.7.x < 11.7.7 / 11.8.x < 11.8.4 Incorrect Authorization (MMSA-2026-00718)

The version of Mattermost Server installed on the remote host is affected by a vulnerability as referenced in the MMSA-2026-00718 advisory. - Mattermost versions 11.7.x = 11.7.6, 11.8.x = 11.8.3 The access control policy unassign endpoint fails to re-validate that each target channel still belong...

CVE-2026-15754

Mattermost versions 11.7.x = 11.7.6, 11.8.x = 11.8.3 The access control policy unassign endpoint fails to re-validate that each target channel still belongs to the requesting admin's team, which allows an authenticated team administrator to remove ABAC attribute-based access control policy...

PT-2026-76668

Mattermost versions 11.7.x = 11.7.6, 11.8.x = 11.8.3 The access control policy unassign endpoint fails to re-validate that each target channel still belongs to the requesting admin's team, which allows an authenticated team administrator to remove ABAC attribute-based access control policy...