HIGH8.1
GO-2026-5495
Mattermost doesn't validate CSRF tokens on an authentication endpoint in github.com/mattermost/mattermost-server
Quick fix
GO-2026-5495 — github.com/mattermost/mattermost-server: upgrade to the fixed version with the command below.
go get github.com/mattermost/mattermost-server@v11.3.3+incompatibleDetails
Mattermost doesn't validate CSRF tokens on an authentication endpoint in github.com/mattermost/mattermost-server
Are you affected?
Enter the version of the package you're using.
Affected packages
Go/github.com/mattermost/mattermost-server
Introduced in:
11.3.0-rc1+incompatibleFixed in: 11.3.3+incompatibleFix
go get github.com/mattermost/mattermost-server@v11.3.3+incompatibleGo/github.com/mattermost/mattermost-server/v5
Introduced in:
0No fixed version published yet for github.com/mattermost/mattermost-server/v5 (go modules). Pin to a known-safe version or switch to an alternative.
Go/github.com/mattermost/mattermost-server/v6
Introduced in:
0No fixed version published yet for github.com/mattermost/mattermost-server/v6 (go modules). Pin to a known-safe version or switch to an alternative.
Go/github.com/mattermost/mattermost/server/v8
Introduced in:
8.0.0-20250721062209-4952acea88ceFixed in: 8.0.0-20260220133927-c29cf05d40f8Fix
go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260220133927-c29cf05d40f8