EUVD-2026-102813

Mattermost versions 11.10.x = 11.10.0, 11.7.x = 11.7.9, 11.9.x = 11.9.1, 11.8.x = 11.8.5 fail to enforce DM/GM check on server side which allows an authenticated user to quarantine a post belonging to DM or GM via direct API call.. Mattermost Advisory ID: MMSA-2026-00756...

CVE-2026-18795

Mattermost versions 11.10.x = 11.10.0, 11.7.x = 11.7.9, 11.9.x = 11.9.1, 11.8.x = 11.8.5 fail to enforce DM/GM check on server side which allows an authenticated user to quarantine a post belonging to DM or GM via direct API call.. Mattermost Advisory ID: MMSA-2026-00756...

CVE-2026-18795: Missing Authorization

Mattermost versions 11.10.x = 11.10.0, 11.7.x = 11.7.9, 11.9.x = 11.9.1, 11.8.x = 11.8.5 fail to enforce DM/GM check on server side which allows an authenticated user to quarantine a post belonging to DM or GM via direct API call.. Mattermost Advisory ID: MMSA-2026-00756...