CVE-2025-53971

Channel and Team Membership APIs inadvertently allow loss of Member privileges.

State: Published
Severity: 3.8 Low
Published: Aug 21, 2025
Updated: Aug 21, 2025
Reserved: Jul 22, 2025

Description

Mattermost versions 10.5.x <= 10.5.8, 9.11.x <= 9.11.17 fail to properly validate authorization for team scheme role modifications which allows Team Admins to demote Team Members to Guests via the PUT /api/v4/teams/team-id/members/user-id/schemeRoles API endpoint.

Scores

CVSS	Score	Vector	Source
3.1	3.8 Low	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N	Mattermost

Weaknesses

CWE-863 Incorrect Authorization

Affected Products

Product	Versions
MattermostMattermost	10.5.0 through 10.5.8Affected 9.11.0 through 9.11.17Affected 10.10.0Not affected 10.5.9Not affected 9.11.18Not affected

References

https://mattermost.com/security-updates

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