Mattermost has an Incorrect Authorization issue

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...

GHSA-XMFH-3CCG-C9FX Mattermost has an Incorrect Authorization issue

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...

PT-2026-51345

Name of the Vulnerable Software and Affected Versions Mattermost version 11.7.0 Mattermost version 10.11.17 Description Insufficient validation of bot targets occurs when demoting users to guests. This allows a lower-privileged administrator to degrade arbitrary bot accounts through the...

CVE-2026-8823: Incorrect Authorization

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...