Description
Mattermost versions 10.5.x <= 10.5.6, 10.8.x <= 10.8.1, 10.7.x <= 10.7.3, 9.11.x <= 9.11.16 fail to verify authorization when retrieving cached posts by PendingPostID which allows an authenticated user to read posts in private channels they don't have access to via guessing the PendingPostID of recently created posts.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mattermost | Mattermost | 10.5.0 – ≤ 10.5.6, 10.8.0 – ≤ 10.8.1, 10.7.0 – ≤ 10.7.3, 9.11.0 – ≤ 9.11.16 | 10.9.0 |
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 | 0.0.20250730T213748-1.1 | openSUSE-SU-2025:15405-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | >= 10.5.0, < 10.5.7 | 10.5.7 | GHSA-7h34-9chr-58qh |
| Go | github.com/mattermost/mattermost-server | >= 10.8.0, < 10.8.2 | 10.8.2 | GHSA-7h34-9chr-58qh |
| Go | github.com/mattermost/mattermost-server | >= 10.7.0, < 10.7.4 | 10.7.4 | GHSA-7h34-9chr-58qh |
| Go | github.com/mattermost/mattermost-server | >= 9.11.0, < 9.11.17 | 9.11.17 | GHSA-7h34-9chr-58qh |
| Go | github.com/mattermost/mattermost-server | >= 9.11.0+incompatible, < 9.11.17+incompatible · >= 10.5.0+incompatible, < 10.5.7+incompatible · >= 10.7.0+incompatible, < 10.7.4+incompatible · >= 10.8.0+incompatible, < 10.8.2+incompatible | 9.11.17+incompatible, 10.5.7+incompatible, 10.7.4+incompatible, 10.8.2+incompatible | GO-2025-3819 |
| Go | github.com/mattermost/mattermost-server/v5 | all versions | — | GO-2025-3819 |
| Go | github.com/mattermost/mattermost-server/v6 | all versions | — | GO-2025-3819 |
| Go | github.com/mattermost/mattermost/server/v8 | < 8.0.0-20250520130510-fa40a8c5d47f | 8.0.0-20250520130510-fa40a8c5d47f | GHSA-7h34-9chr-58qh |
Advisories 1
- openSUSE-SU-2025:15405-1 govulncheck-vulndb-0.0.20250730T213748-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026