Go/github.com/mattermost/mattermost/server/v8 CVE-2026-28759: medium 4.3, EPSS 0.15%
Mattermost does not verify remote cluster channel access when processing shared channel membership removals in github.com/mattermost/mattermost-server
Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260216150504-8738f8c4b3d4 or later.
go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260216150504-8738f8c4b3d4Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | 8.0.0-20260216150504-8738f8c4b3d4 | - |
Fixed versions
| 8.0.0-20260216150504-8738f8c4b3d4 |
Sources
- osv: GO-2026-5256#Go/github.com/mattermost/mattermost/server/v8
- nvd: CVE-2026-28759
- https://github.com/advisories/GHSA-8h9w-w78c-vvr3
- https://github.com/mattermost/mattermost/commit/8738f8c4b3d42b2b687a6231e72f313357a2e891
- https://mattermost.com/security-updates
CVE-2026-28759 · published · modified · JSON