CVE-2025-12559
Medium
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
SeverityMedium
CVSS4.3
Exploit probability—
Product
Mattermost Server
PublishedNov 27, 2025
First seenNov 27, 2025
Weakness typeCWE-200Sensitive information exposure
How to fix
Update
- mattermost mattermost_server10.5.13, 10.11.5, 10.12.2, 11.0.3 or later
- github.com/mattermost/mattermost/server/v88.0.0-20251015091448-abbf01b9db45 or later
- github.com/mattermost/mattermost-server11.0.3, 10.12.2, 10.11.5, 10.5.13 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mattermost mattermost_server | 10.5.0 ≤ v < 10.5.13, 10.11.0 ≤ v < 10.11.5, 10.12.0 ≤ v < 10.12.2, 11.0.0 ≤ v < 11.0.3 | 10.5.13, 10.11.5, 10.12.2, 11.0.3 |
| github.com/mattermost/mattermost/server/v8Go | v < 8.0.0-20251015091448-abbf01b9db45 | 8.0.0-20251015091448-abbf01b9db45 |
| github.com/mattermost/mattermost-serverGo | 11.0.0 ≤ v < 11.0.3, 10.12.0 ≤ v < 10.12.2, 10.11.0 ≤ v < 10.11.5, 10.5.0 ≤ v < 10.5.13, No range specified | 11.0.3, 10.12.2, 10.11.5, 10.5.13 |
| github.com/mattermost/mattermost-server/v5Go | No range specified | — |
| github.com/mattermost/mattermost-server/v6Go | No range specified | — |
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