MEDIUM6.4
GHSA-mxq2-5jpg-7474
Mattermost doesn't validate channel ownership of an existing subscription before applying edits
Quick fix
GHSA-mxq2-5jpg-7474 — 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 validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650
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