PT-2026-32417

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.2 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3 that could have allowed an authenticated user with custom role permissions to demote or remove higher-privileged group members due to improper authorization...

CVE-2026-4916

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.2 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3 that could have allowed an authenticated user with custom role permissions to demote or remove higher-privileged group members due to improper authorization...

EUVD-2025-25413

Malicious code in bioql PyPI...

Improper Authorization

github.com/mattermost/mattermost-server is vulnerable to Improper Authorization. The vulnerability is due to insufficient validation of authorization for team scheme role modifications, which allows an attacker Team Admins to demote Team Members to Guests via the affected API endpoint...

Mattermost Server 9.11.x < 9.11.18 / 10.5.x < 10.5.9 / 10.10.0 Incorrect Authorization (MMSA-2025-00485)

The version of Mattermost Server installed on the remote host is affected by a vulnerability as referenced in the MMSA-2025-00485 advisory. - 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 t...

CVE-2025-53971

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...

GHSA-4276-CM8C-788H 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...

CVE-2025-53971

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...

CVE-2025-53971 Channel and Team Membership APIs inadvertently allow loss of Member privileges.

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...

CVE-2025-53971

Mattermost Server vulnerability CVE-2025-53971 affects versions 10.5.x ≤ 10.5.8 and 9.11.x ≤ 9.11.17. The issue arises from improper authorization validation for team scheme role modifications, allowing Team Admins to demote Team Members to Guests via PUT /api/v4/teams/{team-id}/members/{user-id}...