GHSA-h998-hxxj-8q83 Mattermost doesn't invalidate cached authentication state for active WebSocket connections during global session revocation

• Go github.com/mattermost/mattermost-server: >= 11.7.0, < 11.7.1 → fixed in 11.7.1 • Go github.com/mattermost/mattermost-server: >= 11.6.0, < 11.6.3 → fixed in 11.6.3 • Go github.com/mattermost/mattermost-server: >= 11.5.0, < 11.5.6 → fixed in 11.5.6 • Go github.com/mattermost/mattermost-server: >= 10.11.0, < 10.11.18 → fixed in 10.11.18

Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to invalidate cached authentication state for active WebSocket connections during global session revocation, which allows a user with an existing WebSocket connection to remain authenticated and continue receiving real-time events until the cached session expires or the client reconnects.. Mattermost Advisory ID: MMSA-2026-00664