Description
Mattermost versions 10.7.x <= 10.7.0, 10.5.x <= 10.5.3, 9.11.x <= 9.11.12 fail to properly enforce access controls for guest users accessing channel member information, allowing authenticated guest users to view metadata about members of public channels via the channel members API endpoint.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mattermost | Mattermost | 10.5.0 – ≤ 10.5.3, 9.11.0 – ≤ 9.11.12 | 10.8.0 |
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 Tumbleweed | govulncheck-vulndb | 0.0.20250612T141001-1.1 | openSUSE-SU-2025:15225-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | >= 9.0.0-rc1+incompatible, < 9.11.13+incompatible · >= 10.0.0-rc1+incompatible, < 10.5.4+incompatible · >= 10.6.0-rc1+incompatible, < 10.7.1+incompatible | 9.11.13+incompatible, 10.5.4+incompatible, 10.7.1+incompatible | GO-2025-3730 |
| Go | github.com/mattermost/mattermost-server/v5 | all versions | — | GO-2025-3730 |
| Go | github.com/mattermost/mattermost-server/v6 | all versions | — | GO-2025-3730 |
| Go | github.com/mattermost/mattermost/server/v8 | >= 10.6.0-rc1, < 10.7.1 | 10.7.1 | GHSA-hc6v-386m-93pq |
| Go | github.com/mattermost/mattermost/server/v8 | >= 10.0.0-rc1, < 10.5.4 | 10.5.4 | GHSA-hc6v-386m-93pq |
| Go | github.com/mattermost/mattermost/server/v8 | >= 9.0.0-rc1, < 9.11.13 | 9.11.13 | GHSA-hc6v-386m-93pq |
| Go | github.com/mattermost/mattermost/server/v8 | < 8.0.0-20250414110750-c23f44fe8ed0 | 8.0.0-20250414110750-c23f44fe8ed0 | GHSA-hc6v-386m-93pq |
Advisories 2
- openSUSE-SU-2025:15225-1 govulncheck-vulndb-0.0.20250612T141001-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- WID-SEC-2025-0905 Mattermost: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 11, 2025