GHSA-v549-xx3c-6pc8
Mattermost doesn't check the create_post channel permission during post edit operations
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/mattermost/mattermost/server/v8 | >= 10.11.0, < 10.11.14 | 10.11.14 |
| Go | github.com/mattermost/mattermost/server/v8 | >= 11.4.0, < 11.4.4 | 11.4.4 |
| Go | github.com/mattermost/mattermost/server/v8 | < 8.0.0-20260316171743-090408f09f53 | 8.0.0-20260316171743-090408f09f53 |
| Go | github.com/mattermost/mattermost/server/v8 | >= 11.5.0, < 11.5.2 | 11.5.2 |
| Go | github.com/mattermost/mattermost-server | < 5.3.2-0.20260316171743-090408f09f53 | 5.3.2-0.20260316171743-090408f09f53 |
Details
As written in the advisory (Markdown source, shown as plain text).
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627
References
External links from the advisory. They lead to third-party sites.