Vulnerability DatabaseCVE-2025-53971

CVE-2025-53971:
vulnerability analysis and mitigation

Overview

Mattermost versions 10.5.x <= 10.5.8 and 9.11.x <= 9.11.17 contain an authorization validation vulnerability that affects team scheme role modifications. This vulnerability was disclosed on August 21, 2025 and allows Team Admins to improperly demote Team Members to Guests through the PUT /api/v4/teams/team-id/members/user-id/schemeRoles API endpoint (NVD).

Technical details

The vulnerability is classified as an Incorrect Authorization issue (CWE-863) with a CVSS v3.1 base score of 3.8 (LOW). The attack vector is Network-based (AV:N) with Low attack complexity (AC:L), requires High privileges (PR:H), and no user interaction (UI:N). The scope is Unchanged (S:U) with Low impacts to both Confidentiality (C:L) and Integrity (I:L), while having No impact on Availability (A:N) (NVD).

Impact

The vulnerability allows authenticated Team Admins to improperly modify user roles by demoting Team Members to Guests, potentially leading to unauthorized access level changes within Mattermost teams (NVD).

Exploitability

The vulnerability requires high privileges (Team Admin access) to exploit and can be accessed remotely through the network. No known public exploits have been reported at the time of disclosure (NVD).

Mitigation and workarounds

Users should upgrade to Mattermost version 10.5.9 or later for the 10.5.x series, or version 9.11.18 or later for the 9.11.x series to address this vulnerability (NVD).