CVE-2026-8823

Mattermost versions 11.7.x = 11.7.0, 10.11.x = 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669...

CVE-2026-8823 User Manager can demote bot accounts to guest without bot-management permission

Mattermost versions 11.7.x = 11.7.0, 10.11.x = 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669...

EUVD-2026-38276

Mattermost versions 11.7.x = 11.7.0, 10.11.x = 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669...

CVE-2026-8823

Mattermost versions affected are 11.7.x <= 11.7.0 and 10.11.x

CVE-2023-50333

Mattermost fails to update the permissions of the current session for a user who was just demoted to guest, allowing freshly demoted guests to change group names...