CVE-2025-12559 — Sensitive Information Exposure in Mattermost Mattermost-server

CWE-200 — Sensitive Information Exposure5 documents4 sources
Severity
4.3MEDIUMNVD
EPSS
0.1%
top 83.66%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
4
Github.com Mattermost Mattermost-serverGithub.com Mattermost Mattermost Server V8Mattermost Server+1 more
Timeline
PublishedNov 27
Latest updateDec 15

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

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NExploitability: 2.8 | Impact: 1.4

Affected Packages4 packages

▶NVDmattermost/mattermost_server10.5.0 — 10.5.13+3
▶Gogithub.com/mattermost_mattermost_server_v8< 8.0.0-20251015091448-abbf01b9db45
▶CVEListV5mattermost/mattermost11.0.0 — 11.0.2+3

🔴Vulnerability Details

4
OSV
Mattermost fails to sanitize team email addresses in github.com/mattermost/mattermost-server↗2025-12-15
▶
CVEList
Information Disclosure in Common Teams API↗2025-11-27
▶
OSV
Mattermost fails to sanitize team email addresses↗2025-11-27
▶
GHSA
Mattermost fails to sanitize team email addresses↗2025-11-27
▶
CVE-2025-12559 — Sensitive Information Exposure | cvebase