CVE-2026-8821

Mattermost versions 11.9.0, 11.8.4, 11.7.7, and 10.11.22 (and below within their respective branches) contain a permission bypass in the Playbooks feature. During playbook run creation, the system fails to validate the channel member-management permission, allowing an authenticated channel member...

CVE-2026-16046

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to enforce run-state validation on write operations for finished playbook runs which allows a run participant to modify status, checklists, retrospective content, ownership, and participants on completed runs via REST and GraphQL API...

CVE-2026-16046 Missing run-state validation on finished playbook runs

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to enforce run-state validation on write operations for finished playbook runs which allows a run participant to modify status, checklists, retrospective content, ownership, and participants on completed runs via REST and GraphQL API...

CVE-2026-16046

Mattermost versions 11.7.x ≤ 11.7.6 and 10.11.x ≤ 10.11.21 lack run-state validation on write operations for completed playbook runs, enabling authenticated participants to alter status, checklists, retrospective content, ownership, and participants via REST and GraphQL APIs. No patch version or ...

CVE-2026-16046 Missing run-state validation on finished playbook runs

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to enforce run-state validation on write operations for finished playbook runs which allows a run participant to modify status, checklists, retrospective content, ownership, and participants on completed runs via REST and GraphQL API...

EUVD-2026-60207

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to enforce run-state validation on write operations for finished playbook runs which allows a run participant to modify status, checklists, retrospective content, ownership, and participants on completed runs via REST and GraphQL API...

CVE-2026-16046

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to enforce run-state validation on write operations for finished playbook runs which allows a run participant to modify status, checklists, retrospective content, ownership, and participants on completed runs via REST and GraphQL API...

PT-2026-76660

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to enforce run-state validation on write operations for finished playbook runs which allows a run participant to modify status, checklists, retrospective content, ownership, and participants on completed runs via REST and GraphQL API...

SUSE CVE-2026-4055

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

CVE-2026-4055

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

Mattermost has an Incorrect Authorization issue

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

GHSA-6CFR-WP44-6QMV Mattermost has an Incorrect Authorization issue

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

CVE-2026-4055 Insufficient permission validation on cross-team playbook run creation

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

CVE-2026-4055 Insufficient permission validation on cross-team playbook run creation

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

CVE-2026-4055

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

EUVD-2026-31221

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

CVE-2026-4055 Insufficient permission validation on cross-team playbook run creation

Mattermost versions 11.5.x = 11.5.1 fail to validate team-level runcreate permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request...

PT-2026-42404

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.5.x through 11.5.1 Description An incorrect authorization issue exists during the creation of a playbook run. The system fails to validate the team-level run create permission against the target team. This allows an...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via the playbook run API when the runcreate permission is not verified for an empty playbookId. An attacker can initiate unauthorized playbook runs by sending crafted API requests. Remediation Upgrade...

CVE-2026-26304 Permission Bypass in Playbook Run Creation

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2 fail to verify runcreate permission for empty playbookId, which allows team members to create unauthorized runs via the playbook run API. Mattermost Advisory ID: MMSA-2025-00542...