CVE-2026-80195: Improper Enforcement of Behavioral Workflow

Kimai before 2.63.0 contains a business logic / improper authorization vulnerability in the team update API endpoint PATCH /api/teams/id, which removes all existing team members before validating the submitted replacement member list. An authenticated teamlead or other user with permission to edi...

CVE-2026-80195 Kimai before 2.63.0 Team Membership Removal via API

Kimai before 2.63.0 contains a business logic / improper authorization vulnerability in the team update API endpoint PATCH /api/teams/id, which removes all existing team members before validating the submitted replacement member list. An authenticated teamlead or other user with permission to edi...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

PT-2026-41640

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.5.0 through 11.5.1 Mattermost versions 10.11.0 through 10.11.13 Mattermost versions 11.4.0 through 11.4.3 Description An issue exists during shared channel membership sync where the system fails to validate if a remote...

CVE-2026-28759: Incorrect Authorization

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-41662 Admidio: Missing Minimum Administrator Check in Role Membership Removal

Admidio is an open-source user management solution. Prior to version 5.0.9, Role::stopMembership does not verify whether removing a user from the administrator role leaves zero administrators. The deprecated Membership::stopMembership contains this safety check, but the current code path bypasses...

CVE-2026-41662 Admidio: Missing Minimum Administrator Check in Role Membership Removal

Admidio is an open-source user management solution. Prior to version 5.0.9, Role::stopMembership does not verify whether removing a user from the administrator role leaves zero administrators. The deprecated Membership::stopMembership contains this safety check, but the current code path bypasses...

Admidio Missing Minimum Administrator Check in Role Membership Removal

Summary Role::stopMembership does not verify whether removing a user from the administrator role leaves zero administrators. The deprecated Membership::stopMembership contains this safety check, but the current code path bypasses it. Any administrator can remove the last remaining other...