CVE-2026-26230

A permissions validation flaw has been discovered in mattermost server. Affected versions fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mitigation Mitigation for this issue is either not...

CVE-2026-26230 Team Admin Privilege Escalation to Demote Members to Guest

Mattermost versions 10.11.x = 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531...

CVE-2026-26230 Team Admin Privilege Escalation to Demote Members to Guest

Mattermost versions 10.11.x = 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531...

CVE-2026-26230

Mattermost: Affected software is Mattermost 10.11.x up to 10.11.10. The issue arises from improper validation of permission requirements in the team member roles API endpoint, enabling a team administrator to demote members to the guest role. Root cause is insufficient permission checks in that e...

Mattermost Fails to Properly Validate Team Role Modification

Mattermost versions 10.5.x = 10.5.8, 9.11.x = 9.11.17 fail to properly validate authorization for team scheme role modifications which allows Team Admins to demote Team Members to Guests via the PUT /api/v4/teams/team-id/members/user-id/schemeRoles API endpoint...

Mattermost 安全漏洞

Mattermost is an open source collaboration platform from Mattermost, Inc. in the United States. A security vulnerability exists in Mattermost that stems from the presence of an issue where a team administrator can demote a user to guest via an HTTP request. The vulnerability affects the following...