Go/github.com/mattermost/mattermost-server/v6 CVE-2026-27656: medium 6.1, EPSS 0.18%
Mattermost allows attackers to take over arbitrary user accounts via overly permissive substring matching flaw in github.com/mattermost/mattermost-server
Action: No fix published. Pin and monitor.
Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | - | - |
Fixed versions
No fixed version in the source.
Sources
- osv: GO-2026-5360#Go/github.com/mattermost/mattermost-server/v6
- nvd: CVE-2026-27656
- https://github.com/advisories/GHSA-fg35-5rf6-qg3g
- https://mattermost.com/security-updates
CVE-2026-27656 · published · modified · JSON