CVE-2025-53971CWE-863

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

Low · published August 21, 2025

CVSS v3.1
3.8
EPSS
0%
Percentile
9.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
3.8 · LOW
Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00203 · 9.8th percentile
Weakness
CWE-863 · Incorrect Authorization
Published
2025-08-21T07:31Z
EPSS history
Timeline
  • 21 AUG 07:31Z
    Channel and Team Membership APIs inadvertently allow loss of Member privileges.
    cvelistv5