CVE-2026-3115
Mattermost allows authenticated guest users to enumerate user IDs outside their allowed visibility scope in github.com/mattermost/mattermost-server
4.3
MEDIUM
CVSS 3.1
EPSS 0.23%
Description
Mattermost allows authenticated guest users to enumerate user IDs outside their allowed visibility scope in github.com/mattermost/mattermost-server
How to fix CVE-2026-3115
To remediate CVE-2026-3115, upgrade the affected package to a fixed version below.
- —upgrade to 10.11.11+incompatible or later
- —no fix listed
- —no fix listed
- —upgrade to 11.4.1 or later
- —upgrade to 8.0.0-20260217110922-b7d4a1f1f59b or later
Is CVE-2026-3115 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (5)
- >= 10.11.0-rc1+incompatible, < 10.11.11+incompatible, >= 11.2.0-rc1+incompatible, < 11.2.3+incompatible, >= 11.3.0-rc1+incompatible, < 11.3.2+incompatible, >= 11.4.0+incompatible, < 11.4.1+incompatible
- from 0
- from 0
- >= 11.4.0, < 11.4.1
- >= 8.0.0-20260105080200-d27a2195068d, < 8.0.0-20260217110922-b7d4a1f1f59b
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N |