MEDIUM4.3
GHSA-h998-hxxj-8q83
Mattermost doesn't invalidate cached authentication state for active WebSocket connections during global session revocation
Quick fix
GHSA-h998-hxxj-8q83 — github.com/mattermost/mattermost-server: upgrade to the fixed version with the command below.
go get github.com/mattermost/mattermost-server@v11.7.1Details
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
Are you affected?
Enter the version of the package you're using.
Affected packages
Go/github.com/mattermost/mattermost-server
Introduced in:
11.7.0Fixed in: 11.7.1Fix
go get github.com/mattermost/mattermost-server@v11.7.1Go/github.com/mattermost/mattermost-server
Introduced in:
11.6.0Fixed in: 11.6.3Fix
go get github.com/mattermost/mattermost-server@v11.6.3Go/github.com/mattermost/mattermost-server
Introduced in:
11.5.0Fixed in: 11.5.6Fix
go get github.com/mattermost/mattermost-server@v11.5.6Go/github.com/mattermost/mattermost-server
Introduced in:
10.11.0Fixed in: 10.11.18Fix
go get github.com/mattermost/mattermost-server@v10.11.18