CVE-2025-12559: mattermost server from 10.5.0 (inclusive), before 10.5.13 (exclusive), from 10.11.0 (inclusive), before 10.11.5…

Affected technology

mattermost server · from 10.5.0 (inclusive), before 10.5.13 (exclusive)
mattermost

mattermost server · from 10.11.0 (inclusive), before 10.11.5 (exclusive)
mattermost

mattermost server · from 10.12.0 (inclusive), before 10.12.2 (exclusive)
mattermost

mattermost server · from 11.0.0 (inclusive), before 11.0.3 (exclusive)
mattermost

Mattermost · 11.0.0 through 11.0.2, 10.12.0 through 10.12.1, 10.11.0 through 10.11.4, 10.5.0 through 10.5.12
Mattermost

Description’s affected range: versions 11.0.x <= 11.0.2

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · Low privileges required · No user interaction required

What an attacker can do

The source says 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. Vendor/CNA’s CVSS 3.1 assessment (base score 4.3/10) rates confidentiality impact as low; integrity and availability impact as none.