GHSA-2549-xh72-qrpm Mattermost Improper Validation of Specified Type of Input vulnerability

• Go github.com/mattermost/mattermost/server/v8: >= 9.11.0, < 9.11.16 → fixed in 9.11.16 • Go github.com/mattermost/mattermost/server/v8: >= 10.0.0, < 10.0.4 → fixed in 10.0.4 • Go github.com/mattermost/mattermost/server/v8: >= 10.1.0, < 10.1.4 → fixed in 10.1.4 • Go github.com/mattermost/mattermost/server/v8: >= 10.2.0, < 10.2.1 → fixed in 10.2.1 • Go github.com/mattermost/mattermost/server/v8: < 8.0.0-20250102081831-64c566a8280b → fixed in 8.0.0-20250102081831-64c566a8280b

Mattermost versions 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly validate post types, which allows attackers to deny service to users with the sysconsole_read_plugins permission via creating a post with the custom_pl_notification type and specific props.