Go/github.com/mattermost/mattermost/server/v8 CVE-2026-27656: medium 5.7, EPSS 0.18%
Mattermost allows attackers to take over arbitrary user accounts via overly permissive substring matching flaw
Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260217110922-b7d4a1f1f59b or later.
go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260217110922-b7d4a1f1f59bAffected
| introduced | fixed | last affected |
|---|---|---|
| 8.0.0-20260105080200-d27a2195068d | 8.0.0-20260217110922-b7d4a1f1f59b | - |
Fixed versions
| 8.0.0-20260217110922-b7d4a1f1f59b |
Sources
- osv: GHSA-fg35-5rf6-qg3g#Go/github.com/mattermost/mattermost/server/v8
- https://nvd.nist.gov/vuln/detail/CVE-2026-27656
- https://github.com/mattermost/mattermost
- https://mattermost.com/security-updates
CVE-2026-27656 · published · modified · JSON