Description
Mattermost versions <11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mattermost | Mattermost | <11 – ≤ <11 | 11.0.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | < 11.1.0 | 11.1.0 | GHSA-xpg8-8xpv-948p |
| Go | github.com/mattermost/mattermost-server | < 11.1.0+incompatible | 11.1.0+incompatible | GO-2025-4128 |
| Go | github.com/mattermost/mattermost-server/v5 | all versions | — | GO-2025-4128 |
| Go | github.com/mattermost/mattermost-server/v6 | all versions | — | GO-2025-4128 |
| Go | github.com/mattermost/mattermost/server/v8 | < 8.0.0-20250912063506-7d8b7b5e4a60 | 8.0.0-20250912063506-7d8b7b5e4a60 | GHSA-xpg8-8xpv-948p |
Advisories 2
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
- WID-SEC-2025-2315 Mattermost Server und Mobile: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 27, 2025