Vulnerability · Published Nov 27, 2025 · Assigned by Mattermost
CVE-2025-12559Information Disclosure in Common Teams API
Medium 4.3
In plain English
A medium-severity information exposure in Mattermost from Mattermost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | 10.11.5 | GHSA-4g87-9x45-cx2h |
| Go | github.com/mattermost/mattermost-server | 11.0.3 | GHSA-4g87-9x45-cx2h |
| Go | github.com/mattermost/mattermost-server | 10.12.2 | GHSA-4g87-9x45-cx2h |
| Go | github.com/mattermost/mattermost-server | 10.5.13 | GHSA-4g87-9x45-cx2h |
| Go | github.com/mattermost/mattermost-server | no fix listed | GO-2025-4169 |
| Go | github.com/mattermost/mattermost-server/v5 | no fix listed | GO-2025-4169 |
| Go | github.com/mattermost/mattermost-server/v6 | no fix listed | GO-2025-4169 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20251015091448-abbf01b9db45 | GO-2025-4169 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20251015091448-abbf01b9db45 | GHSA-4g87-9x45-cx2h |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 11.0.0 – through 11.0.210.12.0 – through 10.12.110.11.0 – through 10.11.410.5.0 – through 10.5.12 |
Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N