CVE-2025-12559

Information Disclosure in Common Teams API

State: Published
Severity: 4.3 Medium
Published: Nov 27, 2025
Updated: Nov 28, 2025
Reserved: Oct 31, 2025

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

Scores

CVSS	Score	Vector	Source
3.1	4.3 Medium	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N	Mattermost

Weaknesses

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Affected Products

Product	Versions
MattermostMattermost	11.0.0 through 11.0.2Affected 10.12.0 through 10.12.1Affected 10.11.0 through 10.11.4Affected 10.5.0 through 10.5.12Affected 11.1.0Not affected 11.0.3Not affected 10.12.2Not affected 10.11.5Not affected 10.5.13Not affected

References

https://mattermost.com/security-updates

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