Описание
Mattermost does not verify remote cluster channel access when processing shared channel membership removals
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, including private channels, via crafted membership sync messages targeting channels the remote cluster is not authorized to access. Mattermost Advisory ID: MMSA-2026-00576.
Пакеты
github.com/mattermost/mattermost/server/v8
>= 11.5.0, < 11.5.2
11.5.2
github.com/mattermost/mattermost/server/v8
>= 10.11.0, < 10.11.14
10.11.14
github.com/mattermost/mattermost/server/v8
>= 11.4.0, < 11.4.4
11.4.4
github.com/mattermost/mattermost/server/v8
< 8.0.0-20260216150504-8738f8c4b3d4
8.0.0-20260216150504-8738f8c4b3d4
github.com/mattermost/mattermost-server
< 5.3.2-0.20260216150504-8738f8c4b3d4
5.3.2-0.20260216150504-8738f8c4b3d4
Связанные уязвимости
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, including private channels, via crafted membership sync messages targeting channels the remote cluster is not authorized to access. Mattermost Advisory ID: MMSA-2026-00576
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 1 ...