GHSA-x3r8-2hmh-89f5 Mattermost has an Invite Token Replay Vulnerability via Channel Membership Manipulation

• Go github.com/mattermost/mattermost: >= 10.12.0, < 10.12.2 → fixed in 10.12.2 • Go github.com/mattermost/mattermost: >= 10.11.0-rc1, < 10.11.5 → fixed in 10.11.5 • Go github.com/mattermost/mattermost: >= 11.0.0-alpha.1, < 11.0.4 → fixed in 11.0.4 • Go github.com/mattermost/mattermost/server/v8: < 8.0.0-20251031095924-e7e23b94e006 → fixed in 8.0.0-20251031095924-e7e23b94e006 • Go github.com/mattermost/mattermost-server: < 11.0.4 → fixed in 11.0.4

Mattermost versions 10.11.x < 10.11.5, 11.0.x < 11.0.4, 10.12.x < 10.12.2 fail to invalidate remote cluster invite tokens when using the legacy (version 1) protocol or when the confirming party does not provide a refreshed token, which allows an attacker who has obtained an invite token to authenticate as the remote cluster and perform limited actions on shared channels even after the invitation has been legitimately confirmed.