What is CVE-2025-53971?

CVE-2025-53971 is a low-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 3.8/10. Published 2025-08-21.

How severe is CVE-2025-53971?

Low severity. CVSS v3 base score is 3.8 out of 10.

Auth bypass in Mattermost

CVE-2025-53971

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.

Vulnerability class: Broken Access Control

EPSS: 0.002 (10.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.8 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N.

Affected products

Mattermost — versions 10.5.0, 9.11.0, 10.10.0
Mattermost Mattermost_server

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

responsibledisclosure@mattermost.com (Vendor Advisory)

Frequently asked questions

What is CVE-2025-53971?: CVE-2025-53971 is a low-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 3.8/10. Published 2025-08-21.
How severe is CVE-2025-53971?: Low severity. CVSS v3 base score is 3.8 out of 10.