Go/github.com/mattermost/mattermost-server CVE-2026-28759: medium 4.3, EPSS 0.15%
Mattermost does not verify remote cluster channel access when processing shared channel membership removals
Action: Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260216150504-8738f8c4b3d4 or later.
go get github.com/mattermost/mattermost-server@v5.3.2-0.20260216150504-8738f8c4b3d4Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | 5.3.2-0.20260216150504-8738f8c4b3d4 | - |
Fixed versions
| 5.3.2-0.20260216150504-8738f8c4b3d4 |
Sources
- osv: GHSA-8h9w-w78c-vvr3#Go/github.com/mattermost/mattermost-server
- https://nvd.nist.gov/vuln/detail/CVE-2026-28759
- https://github.com/mattermost/mattermost/commit/8738f8c4b3d42b2b687a6231e72f313357a2e891
- https://github.com/mattermost/mattermost
- https://mattermost.com/security-updates
CVE-2026-28759 · published · modified · JSON