Medium · published August 17, 2026
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 requests. Mattermost Advisory ID: MMSA-2026-00675
| Product | Versions | Fixed in |
|---|---|---|
| mattermost/mattermost_server | ≥ 10.11.0, < 10.11.22 | 10.11.22 |
| mattermost/mattermost_server | ≥ 11.7.0, < 11.7.7 | 11.7.7 |